diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 0c64df61..a8407c84 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -19,6 +19,7 @@
       <option name="CONTINUATION_INDENT_IN_SUPERTYPE_LISTS" value="false" />
       <option name="CONTINUATION_INDENT_IN_IF_CONDITIONS" value="false" />
       <option name="CONTINUATION_INDENT_IN_ELVIS" value="false" />
+      <option name="WRAP_ELVIS_EXPRESSIONS" value="0" />
     </JetCodeStyleSettings>
     <Objective-C-extensions>
       <file>
diff --git a/app/build.gradle b/app/build.gradle
index f1345fb1..216b9ffc 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -82,7 +82,12 @@ dependencies {
     implementation 'androidx.multidex:multidex:2.0.1'
 
     implementation 'com.takisoft.preferencex:preferencex:1.0.0'
-    implementation "com.firebase:firebase-jobdispatcher:0.8.5"
+
+    implementation "android.arch.work:work-rxjava2:1.0.0"
+    implementation "android.arch.work:work-runtime:1.0.0"
+
+    implementation 'com.squareup.inject:assisted-inject-annotations-dagger2:0.3.2'
+    kapt 'com.squareup.inject:assisted-inject-processor-dagger2:0.3.2'
 
     implementation "com.google.dagger:dagger-android-support:2.21"
     kapt "com.google.dagger:dagger-compiler:2.21"
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index cb24e2aa..81e252cb 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -42,13 +42,6 @@
             android:label="@string/main_title"
             android:theme="@style/WulkanowyTheme.NoActionBar" />
 
-        <service
-            android:name=".services.job.SyncWorker"
-            android:exported="false">
-            <intent-filter>
-                <action android:name="com.firebase.jobdispatcher.ACTION_EXECUTE" />
-            </intent-filter>
-        </service>
         <service
             android:name=".services.widgets.TimetableWidgetService"
             android:permission="android.permission.BIND_REMOTEVIEWS" />
@@ -64,6 +57,12 @@
                 android:resource="@xml/provider_widget_timetable" />
         </receiver>
 
+        <provider
+            android:name="androidx.work.impl.WorkManagerInitializer"
+            android:authorities="${applicationId}.workmanager-init"
+            android:exported="false"
+            tools:node="remove" />
+
         <meta-data
             android:name="io.fabric.ApiKey"
             android:value="${fabric_api_key}" />
diff --git a/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt b/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt
index 59478a51..68fc7c64 100644
--- a/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt
+++ b/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt
@@ -3,6 +3,8 @@ package io.github.wulkanowy
 import android.content.Context
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.multidex.MultiDex
+import androidx.work.Configuration
+import androidx.work.WorkManager
 import com.crashlytics.android.Crashlytics
 import com.crashlytics.android.core.CrashlyticsCore
 import com.jakewharton.threetenabp.AndroidThreeTen
@@ -14,6 +16,7 @@ import io.fabric.sdk.android.Fabric
 import io.github.wulkanowy.BuildConfig.DEBUG
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
 import io.github.wulkanowy.di.DaggerAppComponent
+import io.github.wulkanowy.services.sync.SyncWorkerFactory
 import io.github.wulkanowy.utils.CrashlyticsTree
 import io.github.wulkanowy.utils.DebugLogTree
 import timber.log.Timber
@@ -24,6 +27,9 @@ class WulkanowyApp : DaggerApplication() {
     @Inject
     lateinit var prefRepository: PreferencesRepository
 
+    @Inject
+    lateinit var workerFactory: SyncWorkerFactory
+
     override fun attachBaseContext(base: Context?) {
         super.attachBaseContext(base)
         MultiDex.install(this)
@@ -35,6 +41,7 @@ class WulkanowyApp : DaggerApplication() {
         initializeFabric()
         if (DEBUG) enableDebugLog()
         AppCompatDelegate.setDefaultNightMode(prefRepository.currentTheme)
+        WorkManager.initialize(this, Configuration.Builder().setWorkerFactory(workerFactory).build())
     }
 
     private fun enableDebugLog() {
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/CompletedLessonsDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/CompletedLessonsDao.kt
index 3f2e29b8..6816ceaa 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/CompletedLessonsDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/CompletedLessonsDao.kt
@@ -14,7 +14,7 @@ import javax.inject.Singleton
 interface CompletedLessonsDao {
 
     @Insert
-    fun insertAll(exams: List<CompletedLesson>): List<Long>
+    fun insertAll(exams: List<CompletedLesson>)
 
     @Delete
     fun deleteAll(exams: List<CompletedLesson>)
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/GradeDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/GradeDao.kt
index 629f201d..0bd210b0 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/GradeDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/GradeDao.kt
@@ -16,9 +16,6 @@ interface GradeDao {
     @Insert
     fun insertAll(grades: List<Grade>)
 
-    @Update
-    fun update(grade: Grade)
-
     @Update
     fun updateAll(grade: List<Grade>)
 
@@ -28,6 +25,4 @@ interface GradeDao {
     @Query("SELECT * FROM Grades WHERE semester_id = :semesterId AND student_id = :studentId")
     fun loadAll(semesterId: Int, studentId: Int): Maybe<List<Grade>>
 
-    @Query("SELECT * FROM Grades WHERE is_read = 0 AND semester_id = :semesterId AND student_id = :studentId")
-    fun loadAllNew(semesterId: Int, studentId: Int): Maybe<List<Grade>>
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/LuckyNumberDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/LuckyNumberDao.kt
index 05736e42..afd7905c 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/LuckyNumberDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/LuckyNumberDao.kt
@@ -24,6 +24,6 @@ interface LuckyNumberDao {
     fun delete(luckyNumber: LuckyNumber)
 
     @Query("SELECT * FROM LuckyNumbers WHERE student_id = :studentId AND date = :date")
-    fun loadFromDate(studentId: Int, date: LocalDate): Maybe<LuckyNumber>
+    fun load(studentId: Int, date: LocalDate): Maybe<LuckyNumber>
 
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt
index 5018b690..11d456b9 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt
@@ -12,26 +12,20 @@ import io.reactivex.Maybe
 interface MessagesDao {
 
     @Insert
-    fun insertAll(messages: List<Message>): List<Long>
+    fun insertAll(messages: List<Message>)
 
     @Delete
     fun deleteAll(messages: List<Message>)
 
-    @Update
-    fun update(message: Message)
-
     @Update
     fun updateAll(messages: List<Message>)
 
-    @Query("SELECT * FROM Messages WHERE student_id = :studentId AND real_id = :id")
-    fun loadOne(studentId: Int, id: Int): Maybe<Message>
-
     @Query("SELECT * FROM Messages WHERE student_id = :studentId AND folder_id = :folder ORDER BY date DESC")
-    fun load(studentId: Int, folder: Int): Maybe<List<Message>>
+    fun loadAll(studentId: Int, folder: Int): Maybe<List<Message>>
+
+    @Query("SELECT * FROM Messages WHERE student_id = :studentId AND real_id = :id")
+    fun load(studentId: Int, id: Int): Maybe<Message>
 
     @Query("SELECT * FROM Messages WHERE student_id = :studentId AND removed = 1 ORDER BY date DESC")
     fun loadDeleted(studentId: Int): Maybe<List<Message>>
-
-    @Query("SELECT * FROM Messages WHERE unread = 1 AND student_id = :studentId")
-    fun loadNewMessages(studentId: Int): Maybe<List<Message>>
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/NoteDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/NoteDao.kt
index 89443506..867e06a2 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/NoteDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/NoteDao.kt
@@ -16,9 +16,6 @@ interface NoteDao {
     @Insert
     fun insertAll(notes: List<Note>)
 
-    @Update
-    fun update(note: Note)
-
     @Update
     fun updateAll(notes: List<Note>)
 
@@ -28,6 +25,4 @@ interface NoteDao {
     @Query("SELECT * FROM Notes WHERE student_id = :studentId")
     fun loadAll(studentId: Int): Maybe<List<Note>>
 
-    @Query("SELECT * FROM Notes WHERE is_read = 0 AND student_id = :studentId")
-    fun loadNew(studentId: Int): Maybe<List<Note>>
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/entities/Note.kt b/app/src/main/java/io/github/wulkanowy/data/db/entities/Note.kt
index b089c477..5f3a92ab 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/entities/Note.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/entities/Note.kt
@@ -25,7 +25,7 @@ data class Note(
     var id: Long = 0
 
     @ColumnInfo(name = "is_read")
-    var isRead: Boolean = false
+    var isRead: Boolean = true
 
     @ColumnInfo(name = "is_notified")
     var isNotified: Boolean = true
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/attendance/AttendanceLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/attendance/AttendanceLocal.kt
index 6d953bf5..0f587376 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/attendance/AttendanceLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/attendance/AttendanceLocal.kt
@@ -11,11 +11,6 @@ import javax.inject.Singleton
 @Singleton
 class AttendanceLocal @Inject constructor(private val attendanceDb: AttendanceDao) {
 
-    fun getAttendance(semester: Semester, startDate: LocalDate, endDate: LocalDate): Maybe<List<Attendance>> {
-        return attendanceDb.loadAll(semester.diaryId, semester.studentId, startDate, endDate)
-                .filter { !it.isEmpty() }
-    }
-
     fun saveAttendance(attendance: List<Attendance>) {
         attendanceDb.insertAll(attendance)
     }
@@ -23,4 +18,8 @@ class AttendanceLocal @Inject constructor(private val attendanceDb: AttendanceDa
     fun deleteAttendance(attendance: List<Attendance>) {
         attendanceDb.deleteAll(attendance)
     }
+
+    fun getAttendance(semester: Semester, startDate: LocalDate, endDate: LocalDate): Maybe<List<Attendance>> {
+        return attendanceDb.loadAll(semester.diaryId, semester.studentId, startDate, endDate).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryLocal.kt
index 60da5ef2..2e9a1006 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryLocal.kt
@@ -10,10 +10,6 @@ import javax.inject.Singleton
 @Singleton
 class AttendanceSummaryLocal @Inject constructor(private val attendanceDb: AttendanceSummaryDao) {
 
-    fun getAttendanceSummary(semester: Semester, subjectId: Int): Maybe<List<AttendanceSummary>> {
-        return attendanceDb.loadAll(semester.diaryId, semester.studentId, subjectId).filter { !it.isEmpty() }
-    }
-
     fun saveAttendanceSummary(attendance: List<AttendanceSummary>) {
         attendanceDb.insertAll(attendance)
     }
@@ -21,4 +17,8 @@ class AttendanceSummaryLocal @Inject constructor(private val attendanceDb: Atten
     fun deleteAttendanceSummary(attendance: List<AttendanceSummary>) {
         attendanceDb.deleteAll(attendance)
     }
+
+    fun getAttendanceSummary(semester: Semester, subjectId: Int): Maybe<List<AttendanceSummary>> {
+        return attendanceDb.loadAll(semester.diaryId, semester.studentId, subjectId).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryRepository.kt
index 04b6e4ed..90d39aab 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/attendancesummary/AttendanceSummaryRepository.kt
@@ -16,7 +16,7 @@ class AttendanceSummaryRepository @Inject constructor(
     private val remote: AttendanceSummaryRemote
 ) {
 
-    fun getAttendanceSummary(semester: Semester, subjectId: Int, forceRefresh: Boolean = false): Single<List<AttendanceSummary>>? {
+    fun getAttendanceSummary(semester: Semester, subjectId: Int, forceRefresh: Boolean = false): Single<List<AttendanceSummary>> {
         return local.getAttendanceSummary(semester, subjectId).filter { !forceRefresh }
             .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
                 .flatMap {
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsLocal.kt
index 8ebefb31..9b275908 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsLocal.kt
@@ -11,10 +11,6 @@ import javax.inject.Singleton
 @Singleton
 class CompletedLessonsLocal @Inject constructor(private val completedLessonsDb: CompletedLessonsDao) {
 
-    fun getCompletedLessons(semester: Semester, start: LocalDate, end: LocalDate): Maybe<List<CompletedLesson>> {
-        return completedLessonsDb.loadAll(semester.diaryId, semester.studentId, start, end).filter { !it.isEmpty() }
-    }
-
     fun saveCompletedLessons(completedLessons: List<CompletedLesson>) {
         completedLessonsDb.insertAll(completedLessons)
     }
@@ -22,4 +18,8 @@ class CompletedLessonsLocal @Inject constructor(private val completedLessonsDb:
     fun deleteCompleteLessons(completedLessons: List<CompletedLesson>) {
         completedLessonsDb.deleteAll(completedLessons)
     }
+
+    fun getCompletedLessons(semester: Semester, start: LocalDate, end: LocalDate): Maybe<List<CompletedLesson>> {
+        return completedLessonsDb.loadAll(semester.diaryId, semester.studentId, start, end).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeLocal.kt
index cdd583aa..4983a474 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeLocal.kt
@@ -3,7 +3,6 @@ package io.github.wulkanowy.data.repositories.grade
 import io.github.wulkanowy.data.db.dao.GradeDao
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.data.db.entities.Semester
-import io.reactivex.Completable
 import io.reactivex.Maybe
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -11,27 +10,19 @@ import javax.inject.Singleton
 @Singleton
 class GradeLocal @Inject constructor(private val gradeDb: GradeDao) {
 
-    fun getGrades(semester: Semester): Maybe<List<Grade>> {
-        return gradeDb.loadAll(semester.semesterId, semester.studentId).filter { !it.isEmpty() }
-    }
-
-    fun getNewGrades(semester: Semester): Maybe<List<Grade>> {
-        return gradeDb.loadAllNew(semester.semesterId, semester.studentId)
-    }
-
     fun saveGrades(grades: List<Grade>) {
         gradeDb.insertAll(grades)
     }
 
-    fun updateGrade(grade: Grade): Completable {
-        return Completable.fromCallable { gradeDb.update(grade) }
-    }
-
-    fun updateGrades(grades: List<Grade>): Completable {
-        return Completable.fromCallable { gradeDb.updateAll(grades) }
-    }
-
     fun deleteGrades(grades: List<Grade>) {
         gradeDb.deleteAll(grades)
     }
+
+    fun updateGrades(grades: List<Grade>) {
+        gradeDb.updateAll(grades)
+    }
+
+    fun getGrades(semester: Semester): Maybe<List<Grade>> {
+        return gradeDb.loadAll(semester.semesterId, semester.studentId).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeRepository.kt
index f304ecee..d268a46c 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/grade/GradeRepository.kt
@@ -31,24 +31,28 @@ class GradeRepository @Inject constructor(
                             local.deleteGrades(oldGrades - newGrades)
                             local.saveGrades((newGrades - oldGrades)
                                 .onEach {
-                                    if (it.date >= notifyBreakDate) {
-                                        if (notify) it.isNotified = false
-                                        it.isRead = false
+                                    if (it.date >= notifyBreakDate) it.apply {
+                                        isRead = false
+                                        if (notify) isNotified = false
                                     }
                                 })
                         }
                 }.flatMap { local.getGrades(semester).toSingle(emptyList()) })
     }
 
-    fun getNewGrades(semester: Semester): Single<List<Grade>> {
-        return local.getNewGrades(semester).toSingle(emptyList())
+    fun getUnreadGrades(semester: Semester): Single<List<Grade>> {
+        return local.getGrades(semester).map { it.filter { grade -> !grade.isRead } }.toSingle(emptyList())
+    }
+
+    fun getNotNotifiedGrades(semester: Semester): Single<List<Grade>> {
+        return local.getGrades(semester).map { it.filter { grade -> !grade.isNotified } }.toSingle(emptyList())
     }
 
     fun updateGrade(grade: Grade): Completable {
-        return local.updateGrade(grade)
+        return Completable.fromCallable { local.updateGrades(listOf(grade)) }
     }
 
     fun updateGrades(grades: List<Grade>): Completable {
-        return local.updateGrades(grades)
+        return Completable.fromCallable { local.updateGrades(grades) }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/gradessummary/GradeSummaryLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/gradessummary/GradeSummaryLocal.kt
index 7ccf7154..e74641d3 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/gradessummary/GradeSummaryLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/gradessummary/GradeSummaryLocal.kt
@@ -10,11 +10,6 @@ import javax.inject.Singleton
 @Singleton
 class GradeSummaryLocal @Inject constructor(private val gradeSummaryDb: GradeSummaryDao) {
 
-    fun getGradesSummary(semester: Semester): Maybe<List<GradeSummary>> {
-        return gradeSummaryDb.loadAll(semester.semesterId, semester.studentId)
-                .filter { !it.isEmpty() }
-    }
-
     fun saveGradesSummary(gradesSummary: List<GradeSummary>) {
         gradeSummaryDb.insertAll(gradesSummary)
     }
@@ -22,4 +17,8 @@ class GradeSummaryLocal @Inject constructor(private val gradeSummaryDb: GradeSum
     fun deleteGradesSummary(gradesSummary: List<GradeSummary>) {
         gradeSummaryDb.deleteAll(gradesSummary)
     }
+
+    fun getGradesSummary(semester: Semester): Maybe<List<GradeSummary>> {
+        return gradeSummaryDb.loadAll(semester.semesterId, semester.studentId).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/homework/HomeworkLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/homework/HomeworkLocal.kt
index 2508b18e..55e51fca 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/homework/HomeworkLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/homework/HomeworkLocal.kt
@@ -11,10 +11,6 @@ import javax.inject.Singleton
 @Singleton
 class HomeworkLocal @Inject constructor(private val homeworkDb: HomeworkDao) {
 
-    fun getHomework(semester: Semester, date: LocalDate): Maybe<List<Homework>> {
-        return homeworkDb.loadAll(semester.semesterId, semester.studentId, date).filter { !it.isEmpty() }
-    }
-
     fun saveHomework(homework: List<Homework>) {
         homeworkDb.insertAll(homework)
     }
@@ -22,4 +18,8 @@ class HomeworkLocal @Inject constructor(private val homeworkDb: HomeworkDao) {
     fun deleteHomework(homework: List<Homework>) {
         homeworkDb.deleteAll(homework)
     }
+
+    fun getHomework(semester: Semester, date: LocalDate): Maybe<List<Homework>> {
+        return homeworkDb.loadAll(semester.semesterId, semester.studentId, date).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberLocal.kt
index c645736e..115c8965 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberLocal.kt
@@ -3,7 +3,6 @@ package io.github.wulkanowy.data.repositories.luckynumber
 import io.github.wulkanowy.data.db.dao.LuckyNumberDao
 import io.github.wulkanowy.data.db.entities.LuckyNumber
 import io.github.wulkanowy.data.db.entities.Semester
-import io.reactivex.Completable
 import io.reactivex.Maybe
 import org.threeten.bp.LocalDate
 import javax.inject.Inject
@@ -12,19 +11,19 @@ import javax.inject.Singleton
 @Singleton
 class LuckyNumberLocal @Inject constructor(private val luckyNumberDb: LuckyNumberDao) {
 
-    fun getLuckyNumber(semester: Semester, date: LocalDate): Maybe<LuckyNumber> {
-        return luckyNumberDb.loadFromDate(semester.studentId, date)
-    }
-
     fun saveLuckyNumber(luckyNumber: LuckyNumber) {
         luckyNumberDb.insert(luckyNumber)
     }
 
-    fun updateLuckyNumber(luckyNumber: LuckyNumber): Completable {
-        return Completable.fromCallable { luckyNumberDb.update(luckyNumber) }
+    fun updateLuckyNumber(luckyNumber: LuckyNumber) {
+        luckyNumberDb.update(luckyNumber)
     }
 
     fun deleteLuckyNumber(luckyNumber: LuckyNumber) {
         luckyNumberDb.delete(luckyNumber)
     }
+
+    fun getLuckyNumber(semester: Semester, date: LocalDate): Maybe<LuckyNumber> {
+        return luckyNumberDb.load(semester.studentId, date)
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRepository.kt
index 7b69a058..4036521f 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRepository.kt
@@ -44,7 +44,11 @@ class LuckyNumberRepository @Inject constructor(
             )
     }
 
+    fun getNotNotifiedLuckyNumber(semester: Semester): Maybe<LuckyNumber> {
+        return local.getLuckyNumber(semester, LocalDate.now()).filter { !it.isNotified }
+    }
+
     fun updateLuckyNumber(luckyNumber: LuckyNumber): Completable {
-        return local.updateLuckyNumber(luckyNumber)
+        return Completable.fromCallable { local.updateLuckyNumber(luckyNumber) }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageFolder.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageFolder.kt
new file mode 100644
index 00000000..06f5a1e0
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageFolder.kt
@@ -0,0 +1,7 @@
+package io.github.wulkanowy.data.repositories.message
+
+enum class MessageFolder(val id: Int = 1) {
+    RECEIVED(1),
+    SENT(2),
+    TRASHED(3)
+}
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageLocal.kt
index 7bac6615..e9ab7297 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageLocal.kt
@@ -3,6 +3,7 @@ package io.github.wulkanowy.data.repositories.message
 import io.github.wulkanowy.data.db.dao.MessagesDao
 import io.github.wulkanowy.data.db.entities.Message
 import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.message.MessageFolder.TRASHED
 import io.reactivex.Maybe
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -10,34 +11,26 @@ import javax.inject.Singleton
 @Singleton
 class MessageLocal @Inject constructor(private val messagesDb: MessagesDao) {
 
-    fun getMessage(studentId: Int, id: Int): Maybe<Message> {
-        return messagesDb.loadOne(studentId, id)
-    }
-
-    fun getMessages(studentId: Int, folder: MessageRepository.MessageFolder): Maybe<List<Message>> {
-        return when (folder) {
-            MessageRepository.MessageFolder.TRASHED -> messagesDb.loadDeleted(studentId)
-            else -> messagesDb.load(studentId, folder.id)
-        }.filter { !it.isEmpty() }
-    }
-
-    fun getNewMessages(student: Student): Maybe<List<Message>> {
-        return messagesDb.loadNewMessages(student.studentId)
-    }
-
-    fun saveMessages(messages: List<Message>): List<Long> {
-        return messagesDb.insertAll(messages)
-    }
-
-    fun updateMessage(message: Message) {
-        return messagesDb.update(message)
+    fun saveMessages(messages: List<Message>) {
+        messagesDb.insertAll(messages)
     }
 
     fun updateMessages(messages: List<Message>) {
-        return messagesDb.updateAll(messages)
+        messagesDb.updateAll(messages)
     }
 
     fun deleteMessages(messages: List<Message>) {
         messagesDb.deleteAll(messages)
     }
+
+    fun getMessage(student: Student, id: Int): Maybe<Message> {
+        return messagesDb.load(student.studentId, id)
+    }
+
+    fun getMessages(student: Student, folder: MessageFolder): Maybe<List<Message>> {
+        return when (folder) {
+            TRASHED -> messagesDb.loadDeleted(student.studentId)
+            else -> messagesDb.loadAll(student.studentId, folder.id)
+        }.filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRemote.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRemote.kt
index 6d388471..f4ccde0d 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRemote.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRemote.kt
@@ -16,7 +16,7 @@ import io.github.wulkanowy.api.messages.Recipient as ApiRecipient
 @Singleton
 class MessageRemote @Inject constructor(private val api: Api) {
 
-    fun getMessages(studentId: Int, folder: MessageRepository.MessageFolder): Single<List<Message>> {
+    fun getMessages(studentId: Int, folder: MessageFolder): Single<List<Message>> {
         return api.getMessages(Folder.valueOf(folder.name)).map { messages ->
             messages.map {
                 Message(
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRepository.kt
index 2d78c4cb..9f9a7bdf 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/message/MessageRepository.kt
@@ -7,6 +7,7 @@ import io.github.wulkanowy.data.ApiHelper
 import io.github.wulkanowy.data.db.entities.Message
 import io.github.wulkanowy.data.db.entities.Recipient
 import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.message.MessageFolder.RECEIVED
 import io.reactivex.Completable
 import io.reactivex.Single
 import java.net.UnknownHostException
@@ -21,22 +22,16 @@ class MessageRepository @Inject constructor(
     private val apiHelper: ApiHelper
 ) {
 
-    enum class MessageFolder(val id: Int = 1) {
-        RECEIVED(1),
-        SENT(2),
-        TRASHED(3)
-    }
-
     fun getMessages(student: Student, folder: MessageFolder, forceRefresh: Boolean = false, notify: Boolean = false): Single<List<Message>> {
         return Single.just(apiHelper.initApi(student))
             .flatMap { _ ->
-                local.getMessages(student.studentId, folder).filter { !forceRefresh }
+                local.getMessages(student, folder).filter { !forceRefresh }
                     .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
                         .flatMap {
                             if (it) remote.getMessages(student.studentId, folder)
                             else Single.error(UnknownHostException())
                         }.flatMap { new ->
-                            local.getMessages(student.studentId, folder).toSingle(emptyList())
+                            local.getMessages(student, folder).toSingle(emptyList())
                                 .doOnSuccess { old ->
                                     local.deleteMessages(old - new)
                                     local.saveMessages((new - old)
@@ -44,7 +39,7 @@ class MessageRepository @Inject constructor(
                                             it.isNotified = !notify
                                         })
                                 }
-                        }.flatMap { local.getMessages(student.studentId, folder).toSingle(emptyList()) }
+                        }.flatMap { local.getMessages(student, folder).toSingle(emptyList()) }
                     )
             }
     }
@@ -52,33 +47,35 @@ class MessageRepository @Inject constructor(
     fun getMessage(student: Student, messageId: Int, markAsRead: Boolean = false): Single<Message> {
         return Single.just(apiHelper.initApi(student))
             .flatMap { _ ->
-                local.getMessage(student.studentId, messageId)
+                local.getMessage(student, messageId)
                     .filter { !it.content.isNullOrEmpty() }
                     .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
                         .flatMap {
-                            if (it) local.getMessage(student.studentId, messageId).toSingle()
+                            if (it) local.getMessage(student, messageId).toSingle()
                             else Single.error(UnknownHostException())
                         }
                         .flatMap { dbMessage ->
                             remote.getMessagesContent(dbMessage, markAsRead).doOnSuccess {
-                                local.updateMessage(dbMessage.copy(unread = false).apply {
+                                local.updateMessages(listOf(dbMessage.copy(unread = false).apply {
                                     id = dbMessage.id
                                     content = it
-                                })
+                                }))
                             }
                         }.flatMap {
-                            local.getMessage(student.studentId, messageId).toSingle()
+                            local.getMessage(student, messageId).toSingle()
                         }
                     )
             }
     }
 
-    fun getNewMessages(student: Student): Single<List<Message>> {
-        return local.getNewMessages(student).toSingle(emptyList())
+    fun getNotNotifiedMessages(student: Student): Single<List<Message>> {
+        return local.getMessages(student, RECEIVED)
+            .map { it.filter { message -> !message.isNotified && message.unread } }
+            .toSingle(emptyList())
     }
 
     fun updateMessage(message: Message): Completable {
-        return Completable.fromCallable { local.updateMessage(message) }
+        return Completable.fromCallable { local.updateMessages(listOf(message)) }
     }
 
     fun updateMessages(messages: List<Message>): Completable {
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteLocal.kt
index 3c849e2d..784e61f0 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteLocal.kt
@@ -3,7 +3,6 @@ package io.github.wulkanowy.data.repositories.note
 import io.github.wulkanowy.data.db.dao.NoteDao
 import io.github.wulkanowy.data.db.entities.Note
 import io.github.wulkanowy.data.db.entities.Student
-import io.reactivex.Completable
 import io.reactivex.Maybe
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -11,27 +10,19 @@ import javax.inject.Singleton
 @Singleton
 class NoteLocal @Inject constructor(private val noteDb: NoteDao) {
 
-    fun getNotes(student: Student): Maybe<List<Note>> {
-        return noteDb.loadAll(student.studentId).filter { !it.isEmpty() }
-    }
-
-    fun getNewNotes(student: Student): Maybe<List<Note>> {
-        return noteDb.loadNew(student.studentId)
-    }
-
     fun saveNotes(notes: List<Note>) {
         noteDb.insertAll(notes)
     }
 
-    fun updateNote(note: Note): Completable {
-        return Completable.fromCallable { noteDb.update(note) }
-    }
-
-    fun updateNotes(notes: List<Note>): Completable {
-        return Completable.fromCallable { noteDb.updateAll(notes) }
+    fun updateNotes(notes: List<Note>) {
+        noteDb.updateAll(notes)
     }
 
     fun deleteNotes(notes: List<Note>) {
         noteDb.deleteAll(notes)
     }
+
+    fun getNotes(student: Student): Maybe<List<Note>> {
+        return noteDb.loadAll(student.studentId).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteRepository.kt
index 9d575693..d74bc7ea 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/note/NoteRepository.kt
@@ -30,24 +30,24 @@ class NoteRepository @Inject constructor(
                             local.deleteNotes(old - new)
                             local.saveNotes((new - old)
                                 .onEach {
-                                    if (student.registrationDate <= it.date.atStartOfDay()) {
-                                        if (notify) it.isNotified = false
-                                        it.isRead = false
+                                    if (it.date >= student.registrationDate.toLocalDate()) it.apply {
+                                        isRead = false
+                                        if (notify) isNotified = false
                                     }
                                 })
                         }
                 }.flatMap { local.getNotes(student).toSingle(emptyList()) })
     }
 
-    fun getNewNotes(student: Student): Single<List<Note>> {
-        return local.getNewNotes(student).toSingle(emptyList())
+    fun getNotNotifiedNotes(student: Student): Single<List<Note>> {
+        return local.getNotes(student).map { it.filter { note -> !note.isNotified } }.toSingle(emptyList())
     }
 
     fun updateNote(note: Note): Completable {
-        return local.updateNote(note)
+        return Completable.fromCallable { local.updateNotes(listOf(note)) }
     }
 
     fun updateNotes(notes: List<Note>): Completable {
-        return local.updateNotes(notes)
+        return Completable.fromCallable { local.updateNotes(notes) }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/preferences/PreferencesRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/preferences/PreferencesRepository.kt
index 5996d949..6f301664 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/preferences/PreferencesRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/preferences/PreferencesRepository.kt
@@ -12,7 +12,7 @@ class PreferencesRepository @Inject constructor(
     val context: Context
 ) {
     val startMenuIndex: Int
-        get() = sharedPref.getString(context.getString(R.string.pref_key_start_menu), "0")?.toInt() ?: 0
+        get() = sharedPref.getString(context.getString(R.string.pref_key_start_menu), "0")?.toIntOrNull() ?: 0
 
     val isShowPresent: Boolean
         get() = sharedPref.getBoolean(context.getString(R.string.pref_key_attendance_present), true)
@@ -22,25 +22,24 @@ class PreferencesRepository @Inject constructor(
 
     val currentThemeKey: String = context.getString(R.string.pref_key_theme)
     val currentTheme: Int
-        get() = sharedPref.getString(currentThemeKey, "1")?.toInt() ?: 1
+        get() = sharedPref.getString(currentThemeKey, "1")?.toIntOrNull() ?: 1
 
     val gradePlusModifier: Double
-        get() = sharedPref.getString(context.getString(R.string.pref_key_grade_modifier_plus), "0.0")?.toDouble() ?: 0.0
+        get() = sharedPref.getString(context.getString(R.string.pref_key_grade_modifier_plus), "0.0")?.toDoubleOrNull() ?: 0.0
 
     val gradeMinusModifier: Double
-        get() = sharedPref.getString(context.getString(R.string.pref_key_grade_modifier_minus), "0.0")?.toDouble() ?: 0.0
+        get() = sharedPref.getString(context.getString(R.string.pref_key_grade_modifier_minus), "0.0")?.toDoubleOrNull() ?: 0.0
 
     val gradeColorTheme: String
         get() = sharedPref.getString(context.getString(R.string.pref_key_grade_color_scheme), "vulcan") ?: "vulcan"
 
-
-    val serviceEnablesKey: String = context.getString(R.string.pref_key_services_enable)
+    val serviceEnableKey: String = context.getString(R.string.pref_key_services_enable)
     val isServiceEnabled: Boolean
-        get() = sharedPref.getBoolean(serviceEnablesKey, true)
+        get() = sharedPref.getBoolean(serviceEnableKey, true)
 
     val servicesIntervalKey: String = context.getString(R.string.pref_key_services_interval)
-    val servicesInterval: Int
-        get() = sharedPref.getString(servicesIntervalKey, "60")?.toInt() ?: 60
+    val servicesInterval: Long
+        get() = sharedPref.getString(servicesIntervalKey, "60")?.toLongOrNull() ?: 60
 
     val servicesOnlyWifiKey: String = context.getString(R.string.pref_key_services_wifi_only)
     val isServicesOnlyWifi: Boolean
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/timetable/TimetableLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/timetable/TimetableLocal.kt
index a090a55e..e074ce2a 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/timetable/TimetableLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/timetable/TimetableLocal.kt
@@ -11,11 +11,6 @@ import javax.inject.Singleton
 @Singleton
 class TimetableLocal @Inject constructor(private val timetableDb: TimetableDao) {
 
-    fun getTimetable(semester: Semester, startDate: LocalDate, endDate: LocalDate): Maybe<List<Timetable>> {
-        return timetableDb.loadAll(semester.diaryId, semester.studentId, startDate, endDate)
-            .filter { !it.isEmpty() }
-    }
-
     fun saveTimetable(timetables: List<Timetable>) {
         timetableDb.insertAll(timetables)
     }
@@ -23,4 +18,8 @@ class TimetableLocal @Inject constructor(private val timetableDb: TimetableDao)
     fun deleteTimetable(timetables: List<Timetable>) {
         timetableDb.deleteAll(timetables)
     }
+
+    fun getTimetable(semester: Semester, startDate: LocalDate, endDate: LocalDate): Maybe<List<Timetable>> {
+        return timetableDb.loadAll(semester.diaryId, semester.studentId, startDate, endDate).filter { it.isNotEmpty() }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/di/AppComponent.kt b/app/src/main/java/io/github/wulkanowy/di/AppComponent.kt
index 21c193e5..9e8b24ab 100644
--- a/app/src/main/java/io/github/wulkanowy/di/AppComponent.kt
+++ b/app/src/main/java/io/github/wulkanowy/di/AppComponent.kt
@@ -5,6 +5,7 @@ import dagger.android.AndroidInjector
 import dagger.android.support.AndroidSupportInjectionModule
 import io.github.wulkanowy.WulkanowyApp
 import io.github.wulkanowy.data.RepositoryModule
+import io.github.wulkanowy.services.ServicesModule
 import javax.inject.Singleton
 
 @Singleton
@@ -12,6 +13,7 @@ import javax.inject.Singleton
     AndroidSupportInjectionModule::class,
     AppModule::class,
     RepositoryModule::class,
+    ServicesModule::class,
     BuilderModule::class])
 interface AppComponent : AndroidInjector<WulkanowyApp> {
 
diff --git a/app/src/main/java/io/github/wulkanowy/di/AppModule.kt b/app/src/main/java/io/github/wulkanowy/di/AppModule.kt
index 64ec1cbc..eb3b18f9 100644
--- a/app/src/main/java/io/github/wulkanowy/di/AppModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/di/AppModule.kt
@@ -2,8 +2,6 @@ package io.github.wulkanowy.di
 
 import android.appwidget.AppWidgetManager
 import android.content.Context
-import com.firebase.jobdispatcher.FirebaseJobDispatcher
-import com.firebase.jobdispatcher.GooglePlayDriver
 import com.google.firebase.analytics.FirebaseAnalytics
 import dagger.Module
 import dagger.Provides
@@ -30,10 +28,6 @@ internal class AppModule {
     @Provides
     fun provideFlexibleAdapter() = FlexibleAdapter<AbstractFlexibleItem<*>>(null, null, true)
 
-    @Singleton
-    @Provides
-    fun provideJobDispatcher(context: Context) = FirebaseJobDispatcher(GooglePlayDriver(context))
-
     @Singleton
     @Provides
     fun provideFirebaseAnalyticsHelper(context: Context) = FirebaseAnalyticsHelper(FirebaseAnalytics.getInstance(context))
diff --git a/app/src/main/java/io/github/wulkanowy/di/BuilderModule.kt b/app/src/main/java/io/github/wulkanowy/di/BuilderModule.kt
index 9f4ecb80..359ac45c 100644
--- a/app/src/main/java/io/github/wulkanowy/di/BuilderModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/di/BuilderModule.kt
@@ -3,7 +3,6 @@ package io.github.wulkanowy.di
 import dagger.Module
 import dagger.android.ContributesAndroidInjector
 import io.github.wulkanowy.di.scopes.PerActivity
-import io.github.wulkanowy.services.job.SyncWorker
 import io.github.wulkanowy.services.widgets.TimetableWidgetService
 import io.github.wulkanowy.ui.modules.login.LoginActivity
 import io.github.wulkanowy.ui.modules.login.LoginModule
@@ -32,7 +31,4 @@ internal abstract class BuilderModule {
 
     @ContributesAndroidInjector
     abstract fun bindTimetableWidgetProvider(): TimetableWidgetProvider
-
-    @ContributesAndroidInjector
-    abstract fun bindSyncJob(): SyncWorker
 }
diff --git a/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt b/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt
new file mode 100644
index 00000000..70cbf84c
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt
@@ -0,0 +1,102 @@
+package io.github.wulkanowy.services
+
+import android.app.NotificationManager
+import android.content.Context
+import android.content.Context.NOTIFICATION_SERVICE
+import androidx.core.app.NotificationManagerCompat
+import androidx.work.WorkManager
+import com.squareup.inject.assisted.dagger2.AssistedModule
+import dagger.Binds
+import dagger.Module
+import dagger.Provides
+import dagger.multibindings.IntoSet
+import io.github.wulkanowy.services.sync.works.AttendanceSummaryWork
+import io.github.wulkanowy.services.sync.works.AttendanceWork
+import io.github.wulkanowy.services.sync.works.CompletedLessonWork
+import io.github.wulkanowy.services.sync.works.ExamWork
+import io.github.wulkanowy.services.sync.works.GradeStatisticsWork
+import io.github.wulkanowy.services.sync.works.GradeSummaryWork
+import io.github.wulkanowy.services.sync.works.GradeWork
+import io.github.wulkanowy.services.sync.works.HomeworkWork
+import io.github.wulkanowy.services.sync.works.LuckyNumberWork
+import io.github.wulkanowy.services.sync.works.MessageWork
+import io.github.wulkanowy.services.sync.works.NoteWork
+import io.github.wulkanowy.services.sync.works.RecipientWork
+import io.github.wulkanowy.services.sync.works.TimetableWork
+import io.github.wulkanowy.services.sync.works.Work
+import javax.inject.Singleton
+
+@AssistedModule
+@Module(includes = [AssistedInject_ServicesModule::class])
+abstract class ServicesModule {
+
+    @Module
+    companion object {
+
+        @JvmStatic
+        @Provides
+        fun provideWorkManager() = WorkManager.getInstance()
+
+        @JvmStatic
+        @Singleton
+        @Provides
+        fun provideNotificationManagerCompat(context: Context) = NotificationManagerCompat.from(context)
+
+        @JvmStatic
+        @Singleton
+        @Provides
+        fun provideNotificationManager(context: Context) = context.getSystemService(NOTIFICATION_SERVICE) as NotificationManager
+    }
+
+    @Binds
+    @IntoSet
+    abstract fun provideGradeWork(work: GradeWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideNoteWork(work: NoteWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideAttendanceWork(work: AttendanceWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideGradeSummaryWork(work: GradeSummaryWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideExamWork(work: ExamWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideAttendanceSummaryWork(work: AttendanceSummaryWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideTimetableWork(work: TimetableWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideLuckyNumberWork(work: LuckyNumberWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideCompletedLessonWork(work: CompletedLessonWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideHomeworkWork(work: HomeworkWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideMessageWork(work: MessageWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideRecipientWork(work: RecipientWork): Work
+
+    @Binds
+    @IntoSet
+    abstract fun provideGradeStatistics(work: GradeStatisticsWork): Work
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/job/ServiceHelper.kt b/app/src/main/java/io/github/wulkanowy/services/job/ServiceHelper.kt
deleted file mode 100644
index ecb177cc..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/job/ServiceHelper.kt
+++ /dev/null
@@ -1,57 +0,0 @@
-package io.github.wulkanowy.services.job
-
-import com.firebase.jobdispatcher.Constraint.ON_ANY_NETWORK
-import com.firebase.jobdispatcher.Constraint.ON_UNMETERED_NETWORK
-import com.firebase.jobdispatcher.FirebaseJobDispatcher
-import com.firebase.jobdispatcher.Lifetime.FOREVER
-import com.firebase.jobdispatcher.RetryStrategy.DEFAULT_EXPONENTIAL
-import com.firebase.jobdispatcher.Trigger.executionWindow
-import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
-import io.github.wulkanowy.utils.isHolidays
-import org.threeten.bp.LocalDate
-import timber.log.Timber
-import javax.inject.Inject
-import javax.inject.Singleton
-
-@Singleton
-class ServiceHelper @Inject constructor(
-    private val prefRepository: PreferencesRepository,
-    private val dispatcher: FirebaseJobDispatcher
-) {
-
-    fun reloadFullSyncService() {
-        startFullSyncService(true)
-    }
-
-    fun startFullSyncService(replaceCurrent: Boolean = false) {
-        if (LocalDate.now().isHolidays || !prefRepository.isServiceEnabled) {
-            Timber.d("Services disabled or it's holidays")
-            return
-        }
-
-        dispatcher.mustSchedule(
-            dispatcher.newJobBuilder()
-                .setLifetime(FOREVER)
-                .setRecurring(true)
-                .setService(SyncWorker::class.java)
-                .setTag(SyncWorker.WORK_TAG)
-                .setTrigger(
-                    executionWindow(
-                        prefRepository.servicesInterval * 60,
-                        (prefRepository.servicesInterval + 10) * 60
-                    )
-                )
-                .setConstraints(if (prefRepository.isServicesOnlyWifi) ON_UNMETERED_NETWORK else ON_ANY_NETWORK)
-                .setReplaceCurrent(replaceCurrent)
-                .setRetryStrategy(DEFAULT_EXPONENTIAL)
-                .build()
-        )
-
-        Timber.d("Services started")
-    }
-
-    fun stopFullSyncService() {
-        dispatcher.cancel(SyncWorker.WORK_TAG)
-        Timber.d("Services stopped")
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/job/SyncWorker.kt b/app/src/main/java/io/github/wulkanowy/services/job/SyncWorker.kt
deleted file mode 100644
index 1d0d98b4..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/job/SyncWorker.kt
+++ /dev/null
@@ -1,214 +0,0 @@
-package io.github.wulkanowy.services.job
-
-import com.firebase.jobdispatcher.JobParameters
-import com.firebase.jobdispatcher.SimpleJobService
-import dagger.android.AndroidInjection
-import io.github.wulkanowy.data.repositories.attendance.AttendanceRepository
-import io.github.wulkanowy.data.repositories.completedlessons.CompletedLessonsRepository
-import io.github.wulkanowy.data.repositories.exam.ExamRepository
-import io.github.wulkanowy.data.repositories.grade.GradeRepository
-import io.github.wulkanowy.data.repositories.gradessummary.GradeSummaryRepository
-import io.github.wulkanowy.data.repositories.homework.HomeworkRepository
-import io.github.wulkanowy.data.repositories.luckynumber.LuckyNumberRepository
-import io.github.wulkanowy.data.repositories.message.MessageRepository
-import io.github.wulkanowy.data.repositories.message.MessageRepository.MessageFolder.RECEIVED
-import io.github.wulkanowy.data.repositories.note.NoteRepository
-import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
-import io.github.wulkanowy.data.repositories.recipient.RecipientRepository
-import io.github.wulkanowy.data.repositories.reportingunit.ReportingUnitRepository
-import io.github.wulkanowy.data.repositories.semester.SemesterRepository
-import io.github.wulkanowy.data.repositories.student.StudentRepository
-import io.github.wulkanowy.data.repositories.timetable.TimetableRepository
-import io.github.wulkanowy.services.notification.GradeNotification
-import io.github.wulkanowy.services.notification.LuckyNumberNotification
-import io.github.wulkanowy.services.notification.MessageNotification
-import io.github.wulkanowy.services.notification.NoteNotification
-import io.github.wulkanowy.utils.friday
-import io.github.wulkanowy.utils.isHolidays
-import io.github.wulkanowy.utils.monday
-import io.reactivex.Completable
-import io.reactivex.Maybe
-import io.reactivex.Single
-import io.reactivex.disposables.CompositeDisposable
-import org.threeten.bp.LocalDate
-import timber.log.Timber
-import javax.inject.Inject
-
-class SyncWorker : SimpleJobService() {
-
-    @Inject
-    lateinit var student: StudentRepository
-
-    @Inject
-    lateinit var semester: SemesterRepository
-
-    @Inject
-    lateinit var gradesDetails: GradeRepository
-
-    @Inject
-    lateinit var gradesSummary: GradeSummaryRepository
-
-    @Inject
-    lateinit var attendance: AttendanceRepository
-
-    @Inject
-    lateinit var exam: ExamRepository
-
-    @Inject
-    lateinit var timetable: TimetableRepository
-
-    @Inject
-    lateinit var message: MessageRepository
-
-    @Inject
-    lateinit var note: NoteRepository
-
-    @Inject
-    lateinit var homework: HomeworkRepository
-
-    @Inject
-    lateinit var luckyNumber: LuckyNumberRepository
-
-    @Inject
-    lateinit var completedLessons: CompletedLessonsRepository
-
-    @Inject
-    lateinit var reportingUnitRepository: ReportingUnitRepository
-
-    @Inject
-    lateinit var recipientRepository: RecipientRepository
-
-    @Inject
-    lateinit var prefRepository: PreferencesRepository
-
-    private val disposable = CompositeDisposable()
-
-    companion object {
-        const val WORK_TAG = "FULL_SYNC"
-    }
-
-    override fun onCreate() {
-        super.onCreate()
-        AndroidInjection.inject(this)
-    }
-
-    override fun onRunJob(job: JobParameters?): Int {
-        Timber.d("Synchronization started")
-
-        val start = LocalDate.now().monday
-        val end = LocalDate.now().friday
-
-        if (start.isHolidays) return RESULT_FAIL_NORETRY
-
-        var error: Throwable? = null
-
-        val notify = prefRepository.isNotificationsEnable
-
-        disposable.add(student.isStudentSaved()
-            .flatMapMaybe { if (it) student.getCurrentStudent().toMaybe() else Maybe.empty() }
-            .flatMap { semester.getCurrentSemester(it, true).map { semester -> semester to it }.toMaybe() }
-            .flatMapCompletable { c ->
-                Completable.merge(
-                    listOf(
-                        gradesDetails.getGrades(c.second, c.first, true, notify).ignoreElement(),
-                        gradesSummary.getGradesSummary(c.first, true).ignoreElement(),
-                        attendance.getAttendance(c.first, start, end, true).ignoreElement(),
-                        exam.getExams(c.first, start, end, true).ignoreElement(),
-                        timetable.getTimetable(c.first, start, end, true).ignoreElement(),
-                        message.getMessages(c.second, RECEIVED, true, notify).ignoreElement(),
-                        note.getNotes(c.second, c.first, true, notify).ignoreElement(),
-                        homework.getHomework(c.first, LocalDate.now(), true).ignoreElement(),
-                        homework.getHomework(c.first, LocalDate.now().plusDays(1), true).ignoreElement(),
-                        luckyNumber.getLuckyNumber(c.first, true, notify).ignoreElement(),
-                        completedLessons.getCompletedLessons(c.first, start, end, true).ignoreElement()
-                    ) + reportingUnitRepository.getReportingUnits(c.second, true)
-                        .flatMapPublisher { reportingUnits ->
-                            Single.merge(reportingUnits.map { recipientRepository.getRecipients(c.second, 2, it, true) })
-                        }.ignoreElements()
-                )
-            }
-            .subscribe({}, { error = it }))
-
-        return if (null === error) {
-            if (notify) sendNotifications()
-            Timber.d("Synchronization successful")
-            RESULT_SUCCESS
-        } else {
-            Timber.e(error, "Synchronization failed")
-            RESULT_FAIL_RETRY
-        }
-    }
-
-    private fun sendNotifications() {
-        sendGradeNotifications()
-        sendMessageNotification()
-        sendNoteNotification()
-        sendLuckyNumberNotification()
-    }
-
-    private fun sendGradeNotifications() {
-        disposable.add(student.getCurrentStudent()
-            .flatMap { semester.getCurrentSemester(it) }
-            .flatMap { gradesDetails.getNewGrades(it) }
-            .map { it.filter { grade -> !grade.isNotified } }
-            .doOnSuccess {
-                if (it.isNotEmpty()) {
-                    Timber.d("Found ${it.size} unread grades")
-                    GradeNotification(applicationContext).sendNotification(it)
-                }
-            }
-            .map { it.map { grade -> grade.apply { isNotified = true } } }
-            .flatMapCompletable { gradesDetails.updateGrades(it) }
-            .subscribe({}, { Timber.e(it, "Grade notifications sending failed") }))
-    }
-
-    private fun sendMessageNotification() {
-        disposable.add(student.getCurrentStudent()
-            .flatMap { message.getNewMessages(it) }
-            .map { it.filter { message -> !message.isNotified } }
-            .doOnSuccess {
-                if (it.isNotEmpty()) {
-                    Timber.d("Found ${it.size} unread messages")
-                    MessageNotification(applicationContext).sendNotification(it)
-                }
-            }
-            .map { it.map { message -> message.apply { isNotified = true } } }
-            .flatMapCompletable { message.updateMessages(it) }
-            .subscribe({}, { Timber.e(it, "Message notifications sending failed") })
-        )
-    }
-
-    private fun sendNoteNotification() {
-        disposable.add(student.getCurrentStudent()
-            .flatMap { note.getNewNotes(it) }
-            .map { it.filter { note -> !note.isNotified } }
-            .doOnSuccess {
-                if (it.isNotEmpty()) {
-                    Timber.d("Found ${it.size} unread notes")
-                    NoteNotification(applicationContext).sendNotification(it)
-                }
-            }
-            .map { it.map { note -> note.apply { isNotified = true } } }
-            .flatMapCompletable { note.updateNotes(it) }
-            .subscribe({}, { Timber.e("Notifications sending failed") })
-        )
-    }
-
-    private fun sendLuckyNumberNotification() {
-        disposable.add(student.getCurrentStudent()
-            .flatMap { semester.getCurrentSemester(it) }
-            .flatMapMaybe { luckyNumber.getLuckyNumber(it) }
-            .filter { !it.isNotified }
-            .doOnSuccess {
-                LuckyNumberNotification(applicationContext).sendNotification(it)
-            }
-            .map { it.apply { isNotified = true } }
-            .flatMapCompletable { luckyNumber.updateLuckyNumber(it) }
-            .subscribe({}, { Timber.e("Lucky number notification sending failed") }))
-    }
-
-    override fun onDestroy() {
-        super.onDestroy()
-        disposable.clear()
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/notification/BaseNotification.kt b/app/src/main/java/io/github/wulkanowy/services/notification/BaseNotification.kt
deleted file mode 100644
index 945d0b15..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/notification/BaseNotification.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-package io.github.wulkanowy.services.notification
-
-import android.app.Notification
-import android.app.NotificationManager
-import android.content.Context
-import android.content.Context.NOTIFICATION_SERVICE
-import android.os.Build.VERSION.SDK_INT
-import android.os.Build.VERSION_CODES.O
-import androidx.core.app.NotificationCompat
-import timber.log.Timber
-import kotlin.random.Random
-
-abstract class BaseNotification(protected val context: Context) {
-
-    protected val notificationManager: NotificationManager by lazy {
-        context.getSystemService(NOTIFICATION_SERVICE) as NotificationManager
-    }
-
-    fun notify(notification: Notification) {
-        notificationManager.notify(Random.nextInt(1000), notification)
-    }
-
-    fun notificationBuilder(channelId: String): NotificationCompat.Builder {
-        if (SDK_INT >= O) createChannel(channelId)
-        return NotificationCompat.Builder(context, channelId)
-    }
-
-    fun cancelAll() {
-        notificationManager.cancelAll()
-        Timber.d("Notifications canceled")
-    }
-
-    abstract fun createChannel(channelId: String)
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/notification/GradeNotification.kt b/app/src/main/java/io/github/wulkanowy/services/notification/GradeNotification.kt
deleted file mode 100644
index df57ec28..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/notification/GradeNotification.kt
+++ /dev/null
@@ -1,60 +0,0 @@
-package io.github.wulkanowy.services.notification
-
-import android.annotation.TargetApi
-import android.app.Notification.VISIBILITY_PUBLIC
-import android.app.NotificationChannel
-import android.app.NotificationManager.IMPORTANCE_HIGH
-import android.app.PendingIntent
-import android.app.PendingIntent.FLAG_UPDATE_CURRENT
-import android.content.Context
-import androidx.core.app.NotificationCompat
-import androidx.core.content.ContextCompat
-import io.github.wulkanowy.R
-import io.github.wulkanowy.data.db.entities.Grade
-import io.github.wulkanowy.ui.modules.main.MainActivity
-import io.github.wulkanowy.ui.modules.main.MainActivity.Companion.EXTRA_START_MENU_INDEX
-import timber.log.Timber
-
-class GradeNotification(context: Context) : BaseNotification(context) {
-
-    private val channelId = "Grade_Notify"
-
-    @TargetApi(26)
-    override fun createChannel(channelId: String) {
-        notificationManager.createNotificationChannel(NotificationChannel(
-            channelId, context.getString(R.string.notify_grade_channel), IMPORTANCE_HIGH
-        ).apply {
-            enableLights(true)
-            enableVibration(true)
-            lockscreenVisibility = VISIBILITY_PUBLIC
-        })
-    }
-
-    fun sendNotification(items: List<Grade>) {
-        notify(notificationBuilder(channelId)
-            .setContentTitle(context.resources.getQuantityString(R.plurals.grade_new_items, items.size, items.size))
-            .setContentText(context.resources.getQuantityString(R.plurals.notify_grade_new_items, items.size, items.size))
-            .setSmallIcon(R.drawable.ic_stat_notify_grade)
-            .setAutoCancel(true)
-            .setDefaults(NotificationCompat.DEFAULT_ALL)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
-            .setContentIntent(
-                PendingIntent.getActivity(context, 0,
-                    MainActivity.getStartIntent(context).putExtra(EXTRA_START_MENU_INDEX, 0),
-                    FLAG_UPDATE_CURRENT
-                )
-            )
-            .setStyle(NotificationCompat.InboxStyle().run {
-                setSummaryText(context.resources.getQuantityString(R.plurals.grade_number_item, items.size, items.size))
-                items.forEach {
-                    addLine("${it.subject}: ${it.entry}")
-                }
-                this
-            })
-            .build()
-        )
-
-        Timber.d("Notification sent")
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/notification/LuckyNumberNotification.kt b/app/src/main/java/io/github/wulkanowy/services/notification/LuckyNumberNotification.kt
deleted file mode 100644
index 9db159aa..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/notification/LuckyNumberNotification.kt
+++ /dev/null
@@ -1,48 +0,0 @@
-package io.github.wulkanowy.services.notification
-
-import android.annotation.TargetApi
-import android.app.Notification
-import android.app.NotificationChannel
-import android.app.NotificationManager
-import android.app.PendingIntent
-import android.content.Context
-import androidx.core.app.NotificationCompat
-import androidx.core.content.ContextCompat
-import io.github.wulkanowy.R
-import io.github.wulkanowy.data.db.entities.LuckyNumber
-import io.github.wulkanowy.ui.modules.main.MainActivity
-
-class LuckyNumberNotification(context: Context) : BaseNotification(context) {
-
-    private val channelId = "Lucky_Number_Notify"
-
-    @TargetApi(26)
-    override fun createChannel(channelId: String) {
-        notificationManager.createNotificationChannel(NotificationChannel(
-            channelId, context.getString(R.string.notify_lucky_number_channel), NotificationManager.IMPORTANCE_HIGH
-        ).apply {
-            enableLights(true)
-            enableVibration(true)
-            lockscreenVisibility = Notification.VISIBILITY_PUBLIC
-        })
-    }
-
-    fun sendNotification(luckyNumber: LuckyNumber) {
-        notify(notificationBuilder(channelId)
-            .setContentTitle(context.getString(R.string.notify_lucky_number_new_item_title))
-            .setContentText(context.getString(R.string.notify_lucky_number_new_item, luckyNumber.luckyNumber))
-            .setSmallIcon(R.drawable.ic_stat_notify_lucky_number)
-            .setAutoCancel(true)
-            .setDefaults(NotificationCompat.DEFAULT_ALL)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
-            .setContentIntent(
-                PendingIntent.getActivity(context, 0,
-                    MainActivity.getStartIntent(context).putExtra(MainActivity.EXTRA_START_MENU_INDEX, 4),
-                    PendingIntent.FLAG_UPDATE_CURRENT
-                )
-            )
-            .build()
-        )
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/notification/MessageNotification.kt b/app/src/main/java/io/github/wulkanowy/services/notification/MessageNotification.kt
deleted file mode 100644
index 8733cada..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/notification/MessageNotification.kt
+++ /dev/null
@@ -1,58 +0,0 @@
-package io.github.wulkanowy.services.notification
-
-import android.annotation.TargetApi
-import android.app.Notification
-import android.app.NotificationChannel
-import android.app.NotificationManager
-import android.app.PendingIntent
-import android.content.Context
-import androidx.core.app.NotificationCompat
-import androidx.core.content.ContextCompat
-import io.github.wulkanowy.R
-import io.github.wulkanowy.data.db.entities.Message
-import io.github.wulkanowy.ui.modules.main.MainActivity
-import timber.log.Timber
-
-class MessageNotification(context: Context) : BaseNotification(context) {
-
-    private val channelId = "Message_Notify"
-
-    @TargetApi(26)
-    override fun createChannel(channelId: String) {
-        notificationManager.createNotificationChannel(NotificationChannel(
-            channelId, context.getString(R.string.notify_message_channel), NotificationManager.IMPORTANCE_HIGH
-        ).apply {
-            enableLights(true)
-            enableVibration(true)
-            lockscreenVisibility = Notification.VISIBILITY_PUBLIC
-        })
-    }
-
-    fun sendNotification(items: List<Message>) {
-        notify(notificationBuilder(channelId)
-            .setContentTitle(context.resources.getQuantityString(R.plurals.message_new_items, items.size, items.size))
-            .setContentText(context.resources.getQuantityString(R.plurals.notify_message_new_items, items.size, items.size))
-            .setSmallIcon(R.drawable.ic_stat_notify_message)
-            .setAutoCancel(true)
-            .setDefaults(NotificationCompat.DEFAULT_ALL)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
-            .setContentIntent(
-                PendingIntent.getActivity(context, 0,
-                    MainActivity.getStartIntent(context).putExtra(MainActivity.EXTRA_START_MENU_INDEX, 4),
-                    PendingIntent.FLAG_UPDATE_CURRENT
-                )
-            )
-            .setStyle(NotificationCompat.InboxStyle().run {
-                setSummaryText(context.resources.getQuantityString(R.plurals.message_number_item, items.size, items.size))
-                items.forEach {
-                    addLine("${it.sender}: ${it.subject}")
-                }
-                this
-            })
-            .build()
-        )
-
-        Timber.d("Notification sent")
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/notification/NoteNotification.kt b/app/src/main/java/io/github/wulkanowy/services/notification/NoteNotification.kt
deleted file mode 100644
index 33c2fdc7..00000000
--- a/app/src/main/java/io/github/wulkanowy/services/notification/NoteNotification.kt
+++ /dev/null
@@ -1,58 +0,0 @@
-package io.github.wulkanowy.services.notification
-
-import android.annotation.TargetApi
-import android.app.Notification
-import android.app.NotificationChannel
-import android.app.NotificationManager
-import android.app.PendingIntent
-import android.content.Context
-import androidx.core.app.NotificationCompat
-import androidx.core.content.ContextCompat
-import io.github.wulkanowy.R
-import io.github.wulkanowy.data.db.entities.Note
-import io.github.wulkanowy.ui.modules.main.MainActivity
-import timber.log.Timber
-
-class NoteNotification(context: Context) : BaseNotification(context) {
-
-    private val channelId = "Note_Notify"
-
-    @TargetApi(26)
-    override fun createChannel(channelId: String) {
-        notificationManager.createNotificationChannel(NotificationChannel(
-            channelId, context.getString(R.string.notify_note_channel), NotificationManager.IMPORTANCE_HIGH
-        ).apply {
-            enableLights(true)
-            enableVibration(true)
-            lockscreenVisibility = Notification.VISIBILITY_PUBLIC
-        })
-    }
-
-    fun sendNotification(items: List<Note>) {
-        notify(notificationBuilder(channelId)
-            .setContentTitle(context.resources.getQuantityString(R.plurals.note_new_items, items.size, items.size))
-            .setContentText(context.resources.getQuantityString(R.plurals.notify_note_new_items, items.size, items.size))
-            .setSmallIcon(R.drawable.ic_stat_notify_note)
-            .setAutoCancel(true)
-            .setDefaults(NotificationCompat.DEFAULT_ALL)
-            .setPriority(NotificationCompat.PRIORITY_HIGH)
-            .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
-            .setContentIntent(
-                PendingIntent.getActivity(context, 0,
-                    MainActivity.getStartIntent(context).putExtra(MainActivity.EXTRA_START_MENU_INDEX, 4),
-                    PendingIntent.FLAG_UPDATE_CURRENT
-                )
-            )
-            .setStyle(NotificationCompat.InboxStyle().run {
-                setSummaryText(context.resources.getQuantityString(R.plurals.note_number_item, items.size, items.size))
-                items.forEach {
-                    addLine("${it.teacher}: ${it.category}")
-                }
-                this
-            })
-            .build()
-        )
-
-        Timber.d("Notification sent")
-    }
-}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/SyncManager.kt b/app/src/main/java/io/github/wulkanowy/services/sync/SyncManager.kt
new file mode 100644
index 00000000..9a730cab
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/SyncManager.kt
@@ -0,0 +1,50 @@
+package io.github.wulkanowy.services.sync
+
+import android.os.Build.VERSION.SDK_INT
+import android.os.Build.VERSION_CODES.O
+import androidx.work.BackoffPolicy.EXPONENTIAL
+import androidx.work.Constraints
+import androidx.work.ExistingPeriodicWorkPolicy.KEEP
+import androidx.work.ExistingPeriodicWorkPolicy.REPLACE
+import androidx.work.NetworkType.METERED
+import androidx.work.NetworkType.UNMETERED
+import androidx.work.PeriodicWorkRequest
+import androidx.work.WorkManager
+import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
+import io.github.wulkanowy.services.sync.channels.NewEntriesChannel
+import io.github.wulkanowy.utils.isHolidays
+import org.threeten.bp.LocalDate.now
+import timber.log.Timber
+import java.util.concurrent.TimeUnit.MINUTES
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class SyncManager @Inject constructor(
+    private val workManager: WorkManager,
+    private val preferencesRepository: PreferencesRepository,
+    newEntriesChannel: NewEntriesChannel
+) {
+
+    init {
+        if (SDK_INT >= O) newEntriesChannel.create()
+        if (now().isHolidays) stopSyncWorker()
+        Timber.i("SyncManager was initialized")
+    }
+
+    fun startSyncWorker(restart: Boolean = false) {
+        if (preferencesRepository.isServiceEnabled && !now().isHolidays) {
+            workManager.enqueueUniquePeriodicWork(SyncWorker::class.java.simpleName, if (restart) REPLACE else KEEP,
+                PeriodicWorkRequest.Builder(SyncWorker::class.java, preferencesRepository.servicesInterval, MINUTES, 10, MINUTES)
+                    .setBackoffCriteria(EXPONENTIAL, 30, MINUTES)
+                    .setConstraints(Constraints.Builder()
+                        .setRequiredNetworkType(if (preferencesRepository.isServicesOnlyWifi) METERED else UNMETERED)
+                        .build())
+                    .build())
+        }
+    }
+
+    fun stopSyncWorker() {
+        workManager.cancelUniqueWork(SyncWorker::class.java.simpleName)
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorker.kt b/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorker.kt
new file mode 100644
index 00000000..53460a0b
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorker.kt
@@ -0,0 +1,45 @@
+package io.github.wulkanowy.services.sync
+
+import android.content.Context
+import androidx.work.ListenableWorker
+import androidx.work.RxWorker
+import androidx.work.WorkerParameters
+import com.squareup.inject.assisted.Assisted
+import com.squareup.inject.assisted.AssistedInject
+import io.github.wulkanowy.data.repositories.semester.SemesterRepository
+import io.github.wulkanowy.data.repositories.student.StudentRepository
+import io.github.wulkanowy.services.sync.works.Work
+import io.reactivex.Completable
+import io.reactivex.Single
+import timber.log.Timber
+
+class SyncWorker @AssistedInject constructor(
+    @Assisted appContext: Context,
+    @Assisted workerParameters: WorkerParameters,
+    private val studentRepository: StudentRepository,
+    private val semesterRepository: SemesterRepository,
+    private val works: Set<@JvmSuppressWildcards Work>
+) : RxWorker(appContext, workerParameters) {
+
+    override fun createWork(): Single<Result> {
+        return studentRepository.getCurrentStudent()
+            .flatMapCompletable { student ->
+                semesterRepository.getCurrentSemester(student, true)
+                    .flatMapCompletable { semester ->
+                        Completable.mergeDelayError(works.map { it.create(student, semester) })
+                    }
+            }
+            .toSingleDefault(Result.success())
+            .onErrorReturn {
+                Timber.e(it, "There was an error during synchronization")
+                Result.retry()
+            }
+    }
+
+    @AssistedInject.Factory
+    interface Factory {
+
+        fun create(appContext: Context, workerParameters: WorkerParameters): ListenableWorker
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorkerFactory.kt b/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorkerFactory.kt
new file mode 100644
index 00000000..aadfc27f
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorkerFactory.kt
@@ -0,0 +1,20 @@
+package io.github.wulkanowy.services.sync
+
+import android.content.Context
+import androidx.work.ListenableWorker
+import androidx.work.WorkerFactory
+import androidx.work.WorkerParameters
+import timber.log.Timber
+import javax.inject.Inject
+
+class SyncWorkerFactory @Inject constructor(private val syncWorkerFactory: SyncWorker.Factory) : WorkerFactory() {
+
+    override fun createWorker(appContext: Context, workerClassName: String, workerParameters: WorkerParameters): ListenableWorker? {
+        return if (workerClassName == SyncWorker::class.java.name) {
+            syncWorkerFactory.create(appContext, workerParameters)
+        } else {
+            Timber.e(IllegalArgumentException("Unknown worker class name: $workerClassName"))
+            null
+        }
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/channels/NewEntriesChannel.kt b/app/src/main/java/io/github/wulkanowy/services/sync/channels/NewEntriesChannel.kt
new file mode 100644
index 00000000..8e24a2a6
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/channels/NewEntriesChannel.kt
@@ -0,0 +1,30 @@
+package io.github.wulkanowy.services.sync.channels
+
+import android.annotation.TargetApi
+import android.app.Notification.VISIBILITY_PUBLIC
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.NotificationManager.IMPORTANCE_HIGH
+import android.content.Context
+import io.github.wulkanowy.R
+import javax.inject.Inject
+
+@TargetApi(26)
+class NewEntriesChannel @Inject constructor(
+    private val notificationManager: NotificationManager,
+    private val context: Context
+) {
+
+    companion object {
+        const val CHANNEL_ID = "new_entries_channel"
+    }
+
+    fun create() {
+        notificationManager.createNotificationChannel(
+            NotificationChannel(CHANNEL_ID, context.getString(R.string.channel_new_entries), IMPORTANCE_HIGH).apply {
+                enableLights(true)
+                enableVibration(true)
+                lockscreenVisibility = VISIBILITY_PUBLIC
+            })
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceSummaryWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceSummaryWork.kt
new file mode 100644
index 00000000..01978c5b
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceSummaryWork.kt
@@ -0,0 +1,17 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.attendancesummary.AttendanceSummaryRepository
+import io.reactivex.Completable
+import javax.inject.Inject
+
+class AttendanceSummaryWork @Inject constructor(
+    private val attendanceSummaryRepository: AttendanceSummaryRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return attendanceSummaryRepository.getAttendanceSummary(semester, -1, true).ignoreElement()
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceWork.kt
new file mode 100644
index 00000000..e4b55b0e
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/AttendanceWork.kt
@@ -0,0 +1,18 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.attendance.AttendanceRepository
+import io.github.wulkanowy.utils.friday
+import io.github.wulkanowy.utils.monday
+import io.reactivex.Completable
+import org.threeten.bp.LocalDate.now
+import javax.inject.Inject
+
+class AttendanceWork @Inject constructor(private val attendanceRepository: AttendanceRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return attendanceRepository.getAttendance(semester, now().monday, now().friday, true)
+            .ignoreElement()
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/CompletedLessonWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/CompletedLessonWork.kt
new file mode 100644
index 00000000..29642ad6
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/CompletedLessonWork.kt
@@ -0,0 +1,21 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.completedlessons.CompletedLessonsRepository
+import io.github.wulkanowy.utils.friday
+import io.github.wulkanowy.utils.monday
+import io.reactivex.Completable
+import org.threeten.bp.LocalDate.now
+import javax.inject.Inject
+
+class CompletedLessonWork @Inject constructor(
+    private val completedLessonsRepository: CompletedLessonsRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return completedLessonsRepository.getCompletedLessons(semester, now().monday, now().friday, true)
+            .ignoreElement()
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/ExamWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/ExamWork.kt
new file mode 100644
index 00000000..8744fcc7
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/ExamWork.kt
@@ -0,0 +1,17 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.exam.ExamRepository
+import io.github.wulkanowy.utils.friday
+import io.github.wulkanowy.utils.monday
+import io.reactivex.Completable
+import org.threeten.bp.LocalDate.now
+import javax.inject.Inject
+
+class ExamWork @Inject constructor(private val examRepository: ExamRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return examRepository.getExams(semester, now().monday, now().friday, true).ignoreElement()
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeStatisticsWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeStatisticsWork.kt
new file mode 100644
index 00000000..1de39a95
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeStatisticsWork.kt
@@ -0,0 +1,16 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.gradestatistics.GradeStatisticsRepository
+import io.reactivex.Completable
+import javax.inject.Inject
+
+class GradeStatisticsWork @Inject constructor(private val gradeStatisticsRepository: GradeStatisticsRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return gradeStatisticsRepository.getGradesStatistics(semester, "Wszystkie", false, true)
+            .ignoreElement()
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeSummaryWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeSummaryWork.kt
new file mode 100644
index 00000000..6de0bc5b
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeSummaryWork.kt
@@ -0,0 +1,14 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.gradessummary.GradeSummaryRepository
+import io.reactivex.Completable
+import javax.inject.Inject
+
+class GradeSummaryWork @Inject constructor(private val gradeSummaryRepository: GradeSummaryRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return gradeSummaryRepository.getGradesSummary(semester, true).ignoreElement()
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeWork.kt
new file mode 100644
index 00000000..66316934
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/GradeWork.kt
@@ -0,0 +1,61 @@
+package io.github.wulkanowy.services.sync.works
+
+import android.app.PendingIntent
+import android.app.PendingIntent.FLAG_UPDATE_CURRENT
+import android.content.Context
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationCompat.DEFAULT_ALL
+import androidx.core.app.NotificationCompat.PRIORITY_HIGH
+import androidx.core.app.NotificationManagerCompat
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.Grade
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.grade.GradeRepository
+import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
+import io.github.wulkanowy.services.sync.channels.NewEntriesChannel
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import io.github.wulkanowy.ui.modules.main.MainActivity.Companion.EXTRA_START_MENU_INDEX
+import io.github.wulkanowy.utils.getCompatColor
+import io.reactivex.Completable
+import javax.inject.Inject
+import kotlin.random.Random
+
+class GradeWork @Inject constructor(
+    private val context: Context,
+    private val notificationManager: NotificationManagerCompat,
+    private val gradeRepository: GradeRepository,
+    private val preferencesRepository: PreferencesRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return gradeRepository.getGrades(student, semester, true, preferencesRepository.isNotificationsEnable)
+            .flatMap { gradeRepository.getNotNotifiedGrades(semester) }
+            .flatMapCompletable {
+                if (it.isNotEmpty()) notify(it)
+                gradeRepository.updateGrades(it.onEach { grade -> grade.isNotified = true })
+            }
+    }
+
+    private fun notify(grades: List<Grade>) {
+        notificationManager.notify(Random.nextInt(Int.MAX_VALUE), NotificationCompat.Builder(context, NewEntriesChannel.CHANNEL_ID)
+            .setContentTitle(context.resources.getQuantityString(R.plurals.grade_new_items, grades.size, grades.size))
+            .setContentText(context.resources.getQuantityString(R.plurals.grade_notify_new_items, grades.size, grades.size))
+            .setSmallIcon(R.drawable.ic_stat_notify_grade)
+            .setAutoCancel(true)
+            .setPriority(PRIORITY_HIGH)
+            .setDefaults(DEFAULT_ALL)
+            .setColor(context.getCompatColor(R.color.colorPrimary))
+            .setContentIntent(
+                PendingIntent.getActivity(context, 0,
+                    MainActivity.getStartIntent(context).putExtra(EXTRA_START_MENU_INDEX, 0), FLAG_UPDATE_CURRENT))
+            .setStyle(NotificationCompat.InboxStyle().run {
+                setSummaryText(context.resources.getQuantityString(R.plurals.grade_number_item, grades.size, grades.size))
+                grades.forEach { addLine("${it.subject}: ${it.entry}") }
+                this
+            })
+            .build()
+        )
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/HomeworkWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/HomeworkWork.kt
new file mode 100644
index 00000000..90d5f1c6
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/HomeworkWork.kt
@@ -0,0 +1,15 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.homework.HomeworkRepository
+import io.reactivex.Completable
+import org.threeten.bp.LocalDate.now
+import javax.inject.Inject
+
+class HomeworkWork @Inject constructor(private val homeworkRepository: HomeworkRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return homeworkRepository.getHomework(semester, now(), true).ignoreElement()
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/LuckyNumberWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/LuckyNumberWork.kt
new file mode 100644
index 00000000..ca7aaac6
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/LuckyNumberWork.kt
@@ -0,0 +1,55 @@
+package io.github.wulkanowy.services.sync.works
+
+import android.app.PendingIntent
+import android.app.PendingIntent.FLAG_UPDATE_CURRENT
+import android.content.Context
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationCompat.DEFAULT_ALL
+import androidx.core.app.NotificationCompat.PRIORITY_HIGH
+import androidx.core.app.NotificationManagerCompat
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.LuckyNumber
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.luckynumber.LuckyNumberRepository
+import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
+import io.github.wulkanowy.services.sync.channels.NewEntriesChannel
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import io.github.wulkanowy.ui.modules.main.MainActivity.Companion.EXTRA_START_MENU_INDEX
+import io.github.wulkanowy.utils.getCompatColor
+import io.reactivex.Completable
+import javax.inject.Inject
+import kotlin.random.Random
+
+class LuckyNumberWork @Inject constructor(
+    private val context: Context,
+    private val notificationManager: NotificationManagerCompat,
+    private val luckyNumberRepository: LuckyNumberRepository,
+    private val preferencesRepository: PreferencesRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return luckyNumberRepository.getLuckyNumber(semester, true, preferencesRepository.isNotificationsEnable)
+            .flatMap { luckyNumberRepository.getNotNotifiedLuckyNumber(semester) }
+            .flatMapCompletable {
+                notify(it)
+                luckyNumberRepository.updateLuckyNumber(it.apply { isNotified = true })
+            }
+    }
+
+    private fun notify(luckyNumber: LuckyNumber) {
+        notificationManager.notify(Random.nextInt(Int.MAX_VALUE), NotificationCompat.Builder(context, NewEntriesChannel.CHANNEL_ID)
+            .setContentTitle(context.getString(R.string.lucky_number_notify_new_item_title))
+            .setContentText(context.getString(R.string.lucky_number_notify_new_item, luckyNumber.luckyNumber))
+            .setSmallIcon(R.drawable.ic_stat_notify_lucky_number)
+            .setAutoCancel(true)
+            .setDefaults(DEFAULT_ALL)
+            .setPriority(PRIORITY_HIGH)
+            .setColor(context.getCompatColor(R.color.colorPrimary))
+            .setContentIntent(
+                PendingIntent.getActivity(context, 0,
+                    MainActivity.getStartIntent(context).putExtra(EXTRA_START_MENU_INDEX, 4), FLAG_UPDATE_CURRENT)
+            )
+            .build())
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/MessageWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/MessageWork.kt
new file mode 100644
index 00000000..7ab2c8d4
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/MessageWork.kt
@@ -0,0 +1,61 @@
+package io.github.wulkanowy.services.sync.works
+
+import android.app.PendingIntent
+import android.app.PendingIntent.FLAG_UPDATE_CURRENT
+import android.content.Context
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationCompat.DEFAULT_ALL
+import androidx.core.app.NotificationCompat.PRIORITY_HIGH
+import androidx.core.app.NotificationManagerCompat
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.message.MessageFolder.RECEIVED
+import io.github.wulkanowy.data.repositories.message.MessageRepository
+import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
+import io.github.wulkanowy.services.sync.channels.NewEntriesChannel
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import io.github.wulkanowy.ui.modules.main.MainActivity.Companion.EXTRA_START_MENU_INDEX
+import io.github.wulkanowy.utils.getCompatColor
+import io.reactivex.Completable
+import javax.inject.Inject
+import kotlin.random.Random
+
+class MessageWork @Inject constructor(
+    private val context: Context,
+    private val notificationManager: NotificationManagerCompat,
+    private val messageRepository: MessageRepository,
+    private val preferencesRepository: PreferencesRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return messageRepository.getMessages(student, RECEIVED, true, preferencesRepository.isNotificationsEnable)
+            .flatMap { messageRepository.getNotNotifiedMessages(student) }
+            .flatMapCompletable {
+                if (it.isNotEmpty()) notify(it)
+                messageRepository.updateMessages(it.onEach { message -> message.isNotified = true })
+            }
+    }
+
+    private fun notify(messages: List<Message>) {
+        notificationManager.notify(Random.nextInt(Int.MAX_VALUE), NotificationCompat.Builder(context, NewEntriesChannel.CHANNEL_ID)
+            .setContentTitle(context.resources.getQuantityString(R.plurals.message_new_items, messages.size, messages.size))
+            .setContentText(context.resources.getQuantityString(R.plurals.message_notify_new_items, messages.size, messages.size))
+            .setSmallIcon(R.drawable.ic_stat_notify_message)
+            .setAutoCancel(true)
+            .setDefaults(DEFAULT_ALL)
+            .setPriority(PRIORITY_HIGH)
+            .setColor(context.getCompatColor(R.color.colorPrimary))
+            .setContentIntent(
+                PendingIntent.getActivity(context, 0,
+                    MainActivity.getStartIntent(context).putExtra(EXTRA_START_MENU_INDEX, 4), FLAG_UPDATE_CURRENT)
+            )
+            .setStyle(NotificationCompat.InboxStyle().run {
+                setSummaryText(context.resources.getQuantityString(R.plurals.message_number_item, messages.size, messages.size))
+                messages.forEach { addLine("${it.sender}: ${it.subject}") }
+                this
+            })
+            .build())
+    }
+}
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/NoteWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/NoteWork.kt
new file mode 100644
index 00000000..d0e8fe21
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/NoteWork.kt
@@ -0,0 +1,61 @@
+package io.github.wulkanowy.services.sync.works
+
+import android.app.PendingIntent
+import android.app.PendingIntent.FLAG_UPDATE_CURRENT
+import android.content.Context
+import androidx.core.app.NotificationCompat
+import androidx.core.app.NotificationCompat.DEFAULT_ALL
+import androidx.core.app.NotificationCompat.PRIORITY_HIGH
+import androidx.core.app.NotificationManagerCompat
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.Note
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.note.NoteRepository
+import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
+import io.github.wulkanowy.services.sync.channels.NewEntriesChannel
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import io.github.wulkanowy.ui.modules.main.MainActivity.Companion.EXTRA_START_MENU_INDEX
+import io.github.wulkanowy.utils.getCompatColor
+import io.reactivex.Completable
+import javax.inject.Inject
+import kotlin.random.Random
+
+class NoteWork @Inject constructor(
+    private val context: Context,
+    private val notificationManager: NotificationManagerCompat,
+    private val noteRepository: NoteRepository,
+    private val preferencesRepository: PreferencesRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return noteRepository.getNotes(student, semester, true, preferencesRepository.isNotificationsEnable)
+            .flatMap { noteRepository.getNotNotifiedNotes(student) }
+            .flatMapCompletable {
+                if (it.isNotEmpty()) notify(it)
+                noteRepository.updateNotes(it.onEach { note -> note.isNotified = true })
+            }
+    }
+
+    private fun notify(notes: List<Note>) {
+        notificationManager.notify(Random.nextInt(Int.MAX_VALUE), NotificationCompat.Builder(context, NewEntriesChannel.CHANNEL_ID)
+            .setContentTitle(context.resources.getQuantityString(R.plurals.note_new_items, notes.size, notes.size))
+            .setContentText(context.resources.getQuantityString(R.plurals.note_notify_new_items, notes.size, notes.size))
+            .setSmallIcon(R.drawable.ic_stat_notify_note)
+            .setAutoCancel(true)
+            .setDefaults(DEFAULT_ALL)
+            .setPriority(PRIORITY_HIGH)
+            .setColor(context.getCompatColor(R.color.colorPrimary))
+            .setContentIntent(
+                PendingIntent.getActivity(context, 0,
+                    MainActivity.getStartIntent(context).putExtra(EXTRA_START_MENU_INDEX, 4), FLAG_UPDATE_CURRENT)
+            )
+            .setStyle(NotificationCompat.InboxStyle().run {
+                setSummaryText(context.resources.getQuantityString(R.plurals.note_number_item, notes.size, notes.size))
+                notes.forEach { addLine("${it.teacher}: ${it.category}") }
+                this
+            })
+            .build())
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/RecipientWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/RecipientWork.kt
new file mode 100644
index 00000000..af8de434
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/RecipientWork.kt
@@ -0,0 +1,24 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.recipient.RecipientRepository
+import io.github.wulkanowy.data.repositories.reportingunit.ReportingUnitRepository
+import io.reactivex.Completable
+import javax.inject.Inject
+
+class RecipientWork @Inject constructor(
+    private val reportingUnitRepository: ReportingUnitRepository,
+    private val recipientRepository: RecipientRepository
+) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return reportingUnitRepository.getReportingUnits(student)
+            .flatMapCompletable { units ->
+                Completable.mergeDelayError(units.map {
+                    recipientRepository.getRecipients(student, 2, it).ignoreElement()
+                })
+            }
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/TimetableWork.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/TimetableWork.kt
new file mode 100644
index 00000000..bccc07c5
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/TimetableWork.kt
@@ -0,0 +1,19 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.timetable.TimetableRepository
+import io.github.wulkanowy.utils.friday
+import io.github.wulkanowy.utils.monday
+import io.reactivex.Completable
+import org.threeten.bp.LocalDate.now
+import javax.inject.Inject
+
+class TimetableWork @Inject constructor(private val timetableRepository: TimetableRepository) : Work {
+
+    override fun create(student: Student, semester: Semester): Completable {
+        return timetableRepository.getTimetable(semester, now().monday, now().friday, true)
+            .ignoreElement()
+    }
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/services/sync/works/Work.kt b/app/src/main/java/io/github/wulkanowy/services/sync/works/Work.kt
new file mode 100644
index 00000000..1601a103
--- /dev/null
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/works/Work.kt
@@ -0,0 +1,11 @@
+package io.github.wulkanowy.services.sync.works
+
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.reactivex.Completable
+
+interface Work {
+
+    fun create(student: Student, semester: Semester): Completable
+}
+
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountPresenter.kt
index 23ef30ce..0fc6cc45 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountPresenter.kt
@@ -2,6 +2,7 @@ package io.github.wulkanowy.ui.modules.account
 
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.data.repositories.student.StudentRepository
+import io.github.wulkanowy.services.sync.SyncManager
 import io.github.wulkanowy.ui.base.BasePresenter
 import io.github.wulkanowy.ui.base.ErrorHandler
 import io.github.wulkanowy.utils.SchedulersProvider
@@ -12,6 +13,7 @@ import javax.inject.Inject
 class AccountPresenter @Inject constructor(
     private val errorHandler: ErrorHandler,
     private val studentRepository: StudentRepository,
+    private val syncManager: SyncManager,
     private val schedulers: SchedulersProvider
 ) : BasePresenter<AccountView>(errorHandler) {
 
@@ -48,6 +50,7 @@ class AccountPresenter @Inject constructor(
                 view?.apply {
                     if (it.isEmpty()) {
                         Timber.i("Logout result: Open login view")
+                        syncManager.stopSyncWorker()
                         openClearLoginView()
                     } else {
                         Timber.i("Logout result: Switch to another student")
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsPresenter.kt
index 765af079..187f2a07 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsPresenter.kt
@@ -62,7 +62,7 @@ class GradeDetailsPresenter @Inject constructor(
         Timber.i("Select mark grades as read")
         disposable.add(studentRepository.getCurrentStudent()
             .flatMap { semesterRepository.getSemesters(it) }
-            .flatMap { gradeRepository.getNewGrades(it.first { item -> item.semesterId == currentSemesterId }) }
+            .flatMap { gradeRepository.getUnreadGrades(it.first { item -> item.semesterId == currentSemesterId }) }
             .map { it.map { grade -> grade.apply { isRead = true } } }
             .flatMapCompletable {
                 Timber.i("Mark as read ${it.size} grades")
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainActivity.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainActivity.kt
index efe5cc3a..5e0ed2b2 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainActivity.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainActivity.kt
@@ -14,7 +14,6 @@ import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem
 import com.ncapdevi.fragnav.FragNavController
 import com.ncapdevi.fragnav.FragNavController.Companion.HIDE
 import io.github.wulkanowy.R
-import io.github.wulkanowy.services.notification.GradeNotification
 import io.github.wulkanowy.ui.base.BaseActivity
 import io.github.wulkanowy.ui.modules.account.AccountDialog
 import io.github.wulkanowy.ui.modules.attendance.AttendanceFragment
@@ -164,10 +163,6 @@ class MainActivity : BaseActivity(), MainView {
         presenter.onBackPressed { super.onBackPressed() }
     }
 
-    override fun cancelNotifications() {
-        GradeNotification(applicationContext).cancelAll()
-    }
-
     override fun openLoginView() {
         startActivity(LoginActivity.getStartIntent(this)
             .apply { addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK) })
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainPresenter.kt
index 57019f00..a2a973c6 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainPresenter.kt
@@ -4,7 +4,7 @@ import com.google.firebase.analytics.FirebaseAnalytics.Event.APP_OPEN
 import com.google.firebase.analytics.FirebaseAnalytics.Param.DESTINATION
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
 import io.github.wulkanowy.data.repositories.student.StudentRepository
-import io.github.wulkanowy.services.job.ServiceHelper
+import io.github.wulkanowy.services.sync.SyncManager
 import io.github.wulkanowy.ui.base.BasePresenter
 import io.github.wulkanowy.ui.base.ErrorHandler
 import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
@@ -17,8 +17,8 @@ class MainPresenter @Inject constructor(
     private val errorHandler: ErrorHandler,
     private val studentRepository: StudentRepository,
     private val prefRepository: PreferencesRepository,
+    private val syncManager: SyncManager,
     private val schedulers: SchedulersProvider,
-    private val serviceHelper: ServiceHelper,
     private val analytics: FirebaseAnalyticsHelper
 ) : BasePresenter<MainView>(errorHandler) {
 
@@ -26,11 +26,11 @@ class MainPresenter @Inject constructor(
         super.onAttachView(view)
         Timber.i("Main view is attached with $initMenuIndex menu index")
         view.run {
-            cancelNotifications()
             startMenuIndex = if (initMenuIndex != -1) initMenuIndex else prefRepository.startMenuIndex
             initView()
         }
-        serviceHelper.startFullSyncService()
+
+        syncManager.startSyncWorker()
 
         analytics.logEvent(APP_OPEN, DESTINATION to when (initMenuIndex) {
             1 -> "Grades"
@@ -92,8 +92,7 @@ class MainPresenter @Inject constructor(
                 if (it.isNotEmpty()) {
                     Timber.i("Switching current student")
                     studentRepository.switchStudent(it[0])
-                }
-                else Completable.complete()
+                } else Completable.complete()
             }
             .subscribeOn(schedulers.backgroundThread)
             .observeOn(schedulers.mainThread)
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainView.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainView.kt
index 112f3f4e..d3d7e342 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainView.kt
@@ -26,8 +26,6 @@ interface MainView : BaseView {
 
     fun popView()
 
-    fun cancelNotifications()
-
     fun openLoginView()
 
     interface MainChildView {
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt
index 0de50299..d8f4b61d 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt
@@ -7,9 +7,9 @@ import android.view.View.INVISIBLE
 import android.view.View.VISIBLE
 import android.view.ViewGroup
 import io.github.wulkanowy.R
-import io.github.wulkanowy.data.repositories.message.MessageRepository.MessageFolder.RECEIVED
-import io.github.wulkanowy.data.repositories.message.MessageRepository.MessageFolder.SENT
-import io.github.wulkanowy.data.repositories.message.MessageRepository.MessageFolder.TRASHED
+import io.github.wulkanowy.data.repositories.message.MessageFolder.RECEIVED
+import io.github.wulkanowy.data.repositories.message.MessageFolder.SENT
+import io.github.wulkanowy.data.repositories.message.MessageFolder.TRASHED
 import io.github.wulkanowy.ui.base.BaseFragment
 import io.github.wulkanowy.ui.base.BaseFragmentPagerAdapter
 import io.github.wulkanowy.ui.modules.main.MainActivity
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt
index a7173064..61572d72 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt
@@ -12,7 +12,7 @@ import eu.davidea.flexibleadapter.common.FlexibleItemDecoration
 import eu.davidea.flexibleadapter.common.SmoothScrollLinearLayoutManager
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.R
-import io.github.wulkanowy.data.repositories.message.MessageRepository
+import io.github.wulkanowy.data.repositories.message.MessageFolder
 import io.github.wulkanowy.ui.base.session.BaseSessionFragment
 import io.github.wulkanowy.ui.modules.main.MainActivity
 import io.github.wulkanowy.ui.modules.message.MessageFragment
@@ -34,7 +34,7 @@ class MessageTabFragment : BaseSessionFragment(), MessageTabView, MessageView.Me
     companion object {
         const val MESSAGE_TAB_FOLDER_ID = "message_tab_folder_id"
 
-        fun newInstance(folder: MessageRepository.MessageFolder): MessageTabFragment {
+        fun newInstance(folder: MessageFolder): MessageTabFragment {
             return MessageTabFragment().apply {
                 arguments = Bundle().apply {
                     putString(MESSAGE_TAB_FOLDER_ID, folder.name)
@@ -56,7 +56,7 @@ class MessageTabFragment : BaseSessionFragment(), MessageTabView, MessageView.Me
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
         messageContainer = messageTabRecycler
-        presenter.onAttachView(this, MessageRepository.MessageFolder.valueOf(
+        presenter.onAttachView(this, MessageFolder.valueOf(
             (savedInstanceState ?: arguments)?.getString(MessageTabFragment.MESSAGE_TAB_FOLDER_ID) ?: ""
         ))
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt
index 3fab138f..cef6e562 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt
@@ -2,6 +2,7 @@ package io.github.wulkanowy.ui.modules.message.tab
 
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
 import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.repositories.message.MessageFolder
 import io.github.wulkanowy.data.repositories.message.MessageRepository
 import io.github.wulkanowy.data.repositories.student.StudentRepository
 import io.github.wulkanowy.ui.base.session.BaseSessionPresenter
@@ -20,9 +21,9 @@ class MessageTabPresenter @Inject constructor(
     private val analytics: FirebaseAnalyticsHelper
 ) : BaseSessionPresenter<MessageTabView>(errorHandler) {
 
-    lateinit var folder: MessageRepository.MessageFolder
+    lateinit var folder: MessageFolder
 
-    fun onAttachView(view: MessageTabView, folder: MessageRepository.MessageFolder) {
+    fun onAttachView(view: MessageTabView, folder: MessageFolder) {
         super.onAttachView(view)
         view.initView()
         this.folder = folder
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
index f75e566f..8e3cbf5f 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
@@ -2,7 +2,7 @@ package io.github.wulkanowy.ui.modules.settings
 
 import com.readystatesoftware.chuck.api.ChuckCollector
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
-import io.github.wulkanowy.services.job.ServiceHelper
+import io.github.wulkanowy.services.sync.SyncManager
 import io.github.wulkanowy.ui.base.BasePresenter
 import io.github.wulkanowy.ui.base.ErrorHandler
 import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
@@ -14,36 +14,25 @@ import javax.inject.Inject
 class SettingsPresenter @Inject constructor(
     errorHandler: ErrorHandler,
     private val preferencesRepository: PreferencesRepository,
-    private val serviceHelper: ServiceHelper,
     private val analytics: FirebaseAnalyticsHelper,
+    private val syncManager: SyncManager,
     private val chuckCollector: ChuckCollector
 ) : BasePresenter<SettingsView>(errorHandler) {
 
     override fun onAttachView(view: SettingsView) {
         super.onAttachView(view)
         Timber.i("Settings view is attached")
-
-        view.run {
-            setServicesSuspended(preferencesRepository.serviceEnablesKey, now().isHolidays)
-        }
+        view.setServicesSuspended(preferencesRepository.serviceEnableKey, now().isHolidays)
     }
 
     fun onSharedPreferenceChanged(key: String) {
         Timber.i("Change settings $key")
-        when (key) {
-            preferencesRepository.serviceEnablesKey -> {
-                if (preferencesRepository.isServiceEnabled) serviceHelper.startFullSyncService()
-                else serviceHelper.stopFullSyncService()
-            }
-            preferencesRepository.servicesIntervalKey,
-            preferencesRepository.servicesOnlyWifiKey -> {
-                serviceHelper.reloadFullSyncService()
-            }
-            preferencesRepository.currentThemeKey -> {
-                view?.setTheme(preferencesRepository.currentTheme)
-            }
-            preferencesRepository.isShowChuckerNotificationKey -> {
-                chuckCollector.showNotification(preferencesRepository.isShowChuckerNotification)
+        preferencesRepository.apply {
+            when (key) {
+                serviceEnableKey -> syncManager.run { if (isServiceEnabled) startSyncWorker() else stopSyncWorker() }
+                servicesIntervalKey, servicesOnlyWifiKey -> syncManager.startSyncWorker(true)
+                currentThemeKey -> view?.setTheme(currentTheme)
+                isShowChuckerNotificationKey -> chuckCollector.showNotification(isShowChuckerNotification)
             }
         }
         analytics.logEvent("setting_changed", "name" to key)
diff --git a/app/src/main/java/io/github/wulkanowy/utils/ContextExtension.kt b/app/src/main/java/io/github/wulkanowy/utils/ContextExtension.kt
index e056bf7e..70368bad 100644
--- a/app/src/main/java/io/github/wulkanowy/utils/ContextExtension.kt
+++ b/app/src/main/java/io/github/wulkanowy/utils/ContextExtension.kt
@@ -3,13 +3,18 @@ package io.github.wulkanowy.utils
 import android.content.Context
 import androidx.annotation.AttrRes
 import androidx.annotation.ColorInt
+import androidx.annotation.ColorRes
+import androidx.core.content.ContextCompat
 
 @ColorInt
 fun Context.getThemeAttrColor(@AttrRes colorAttr: Int): Int {
-    val array = this.obtainStyledAttributes(null, intArrayOf(colorAttr))
-    try {
-        return array.getColor(0, 0)
+    val array = obtainStyledAttributes(null, intArrayOf(colorAttr))
+    return try {
+        array.getColor(0, 0)
     } finally {
         array.recycle()
     }
 }
+
+@ColorInt
+fun Context.getCompatColor(@ColorRes colorRes: Int) = ContextCompat.getColor(this, colorRes)
diff --git a/app/src/main/res/layout/item_login_options.xml b/app/src/main/res/layout/item_login_options.xml
index 39942c02..f13eb601 100644
--- a/app/src/main/res/layout/item_login_options.xml
+++ b/app/src/main/res/layout/item_login_options.xml
@@ -16,8 +16,8 @@
         android:layout_height="40dp"
         android:layout_marginEnd="16dp"
         android:layout_marginRight="16dp"
-        android:tint="@android:color/black"
-        app:srcCompat="@drawable/ic_all_account_24dp" />
+        app:srcCompat="@drawable/ic_all_account_24dp"
+        app:tint="?android:textColorPrimary" />
 
     <TextView
         android:id="@+id/loginItemName"
diff --git a/app/src/main/res/values-pl/strings.xml b/app/src/main/res/values-pl/strings.xml
index 54bceb9b..4c4e8f26 100644
--- a/app/src/main/res/values-pl/strings.xml
+++ b/app/src/main/res/values-pl/strings.xml
@@ -1,6 +1,7 @@
 <resources>
     <string name="app_name">Wulkanowy</string>
 
+
     <!--Activity/Fragment title-->
     <string name="login_title">Wybierz ucznia</string>
     <string name="main_title">Wulkanowy</string>
@@ -70,17 +71,12 @@
         <item quantity="many">%d ocen</item>
         <item quantity="other">%d ocen</item>
     </plurals>
-
     <plurals name="grade_new_items">
         <item quantity="one">Nowa ocena</item>
         <item quantity="few">Nowe oceny</item>
         <item quantity="many">Nowe oceny</item>
     </plurals>
-
-
-    <!--Grade notify-->
-    <string name="notify_grade_channel">Nowe oceny</string>
-    <plurals name="notify_grade_new_items">
+    <plurals name="grade_notify_new_items">
         <item quantity="one">Dostałeś %1$d ocenę</item>
         <item quantity="few">"Dostałeś %1$d oceny</item>
         <item quantity="many">Dostałeś %1$d ocen</item>
@@ -88,16 +84,6 @@
     </plurals>
 
 
-    <!--Note notify-->
-    <string name="notify_note_channel">Nowe uwagi</string>
-    <plurals name="notify_note_new_items">
-        <item quantity="one">Dostałeś %1$d uwagę</item>
-        <item quantity="few">"Dostałeś %1$d uwagi</item>
-        <item quantity="many">Dostałeś %1$d uwag</item>
-        <item quantity="other">Dostałeś %1$d uwag</item>
-    </plurals>
-
-
     <!--Timetable-->
     <string name="timetable_lesson">Lekcja</string>
     <string name="timetable_room">Sala</string>
@@ -106,6 +92,7 @@
     <string name="timetable_changes">Zmiany</string>
     <string name="timetable_no_items">Brak lekcji w tym dniu</string>
 
+
     <!--CompletedLesson-->
     <string name="completed_lessons_title">Lekcje zrealizowane</string>
     <string name="completed_lessons_button">Zobacz lekcje zrealizowane</string>
@@ -114,6 +101,7 @@
     <string name="completed_lessons_absence">Nieobecność</string>
     <string name="completed_lessons_resources">Zasoby</string>
 
+
     <!--Attendance-->
     <string name="attendance_summary_button">Podsumowanie frekwencji</string>
     <string name="attendance_absence_school">Nieobecny z przyczyn szkolnych</string>
@@ -131,9 +119,11 @@
         <item quantity="many">%1$d nieobecności</item>
     </plurals>
 
+
     <!--Attendance summary-->
     <string name="attendance_summary_final">Frekwencja</string>
 
+
     <!--Exam-->
     <string name="exam_no_items">Brak sprawdzianów w tym tygodniu</string>
     <string name="exam_type">Typ</string>
@@ -155,17 +145,12 @@
         <item quantity="few">%d wiadomości</item>
         <item quantity="many">%d wiadomości</item>
     </plurals>
-
     <plurals name="message_new_items">
         <item quantity="one">Nowa wiadomość</item>
         <item quantity="few">Nowe wiadomości</item>
         <item quantity="many">Nowe wiadomości</item>
     </plurals>
-
-
-    <!--Message notify-->
-    <string name="notify_message_channel">Nowe wiadomości</string>
-    <plurals name="notify_message_new_items">
+    <plurals name="message_notify_new_items">
         <item quantity="one">Dostałeś %1$d wiadomość</item>
         <item quantity="few">"Dostałeś %1$d wiadomości</item>
         <item quantity="many">Dostałeś %1$d wiadomości</item>
@@ -181,9 +166,6 @@
     <string name="send_message_required_recipients">Musisz wybrać co najmniej 1 adresata</string>
     <string name="send_message_content_min_length">Treść wiadomości musi zawierać co najmniej 3 znaki</string>
 
-    <!--About-->
-    <string name="about_source_code">Kod źródłowy</string>
-    <string name="about_feedback">Zgłoś błąd</string>
 
     <!--Note-->
     <string name="note_no_items">Brak informacji o uwagach</string>
@@ -193,27 +175,31 @@
         <item quantity="many">%d uwag</item>
         <item quantity="other">%d uwag</item>
     </plurals>
-
     <plurals name="note_new_items">
         <item quantity="one">Nowa uwaga</item>
         <item quantity="few">Nowe uwagi</item>
         <item quantity="many">Nowych uwag</item>
         <item quantity="other">Nowych uwag</item>
     </plurals>
+    <plurals name="note_notify_new_items">
+        <item quantity="one">Dostałeś %1$d uwagę</item>
+        <item quantity="few">"Dostałeś %1$d uwagi</item>
+        <item quantity="many">Dostałeś %1$d uwag</item>
+        <item quantity="other">Dostałeś %1$d uwag</item>
+    </plurals>
 
 
     <!--Homework-->
     <string name="homework_no_items">Brak zadań domowych</string>
 
+
     <!--Lucky number-->
     <string name="lucky_number_title">Szczęśliwy numerek</string>
     <string name="lucky_number_header">Dzisiejszym szczęśliwym numerkiem jest</string>
     <string name="lucky_number_empty">Brak informacji o szczęśliwym numerku</string>
+    <string name="lucky_number_notify_new_item_title">Szczęśliwy numerek na dzisiaj</string>
+    <string name="lucky_number_notify_new_item">Dziś szczęśliwym numerkiem jest: %d</string>
 
-    <!--Lucky number notify-->
-    <string name="notify_lucky_number_channel">Nowe szczęśliwe numerki</string>
-    <string name="notify_lucky_number_new_item_title">Szczęśliwy numerek na dzisiaj</string>
-    <string name="notify_lucky_number_new_item">Dziś szczęśliwym numerkiem jest: %d</string>
 
     <!--Account-->
     <string name="account_add_new">Dodaj konto</string>
@@ -222,6 +208,11 @@
     <string name="account_logout_student">Wylogowanie ucznia</string>
 
 
+    <!--About-->
+    <string name="about_source_code">Kod źródłowy</string>
+    <string name="about_feedback">Zgłoś błąd</string>
+
+
     <!--Generic-->
     <string name="all_content">Treść</string>
     <string name="all_description">Opis</string>
@@ -267,6 +258,10 @@
     <string name="pref_services_wifi">Tylko WiFi</string>
 
 
+    <!--Notification Channels-->
+    <string name="channel_new_entries">Nowe wpisy w dzienniku</string>
+
+
     <!--Colors-->
     <string name="all_black">Czarny</string>
     <string name="all_red">Czerwony</string>
@@ -279,6 +274,7 @@
     <!--Others-->
     <string name="all_copied">Skopiowano</string>
 
+
     <!--Errors-->
     <string name="error_no_internet">Brak połączenia z internetem</string>
     <string name="error_timeout">Zbyt długie oczekiwanie na połączenie</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index b51387e9..d07ecaea 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,6 +1,7 @@
 <resources>
     <string name="app_name">Wulkanowy</string>
 
+
     <!--Activity/Fragment title-->
     <string name="login_title">Select student</string>
     <string name="main_title">Wulkanowy</string>
@@ -68,26 +69,15 @@
         <item quantity="one">%d grade</item>
         <item quantity="other">%d grades</item>
     </plurals>
-
     <plurals name="grade_new_items">
         <item quantity="one">New grade</item>
         <item quantity="other">New grades</item>
     </plurals>
-
-    <!--Grade notify-->
-    <string name="notify_grade_channel">New grades</string>
-    <plurals name="notify_grade_new_items">
+    <plurals name="grade_notify_new_items">
         <item quantity="one">You received %1$d grade</item>
         <item quantity="other">You received %1$d grades</item>
     </plurals>
 
-    <!--Note notify-->
-    <string name="notify_note_channel">New notes</string>
-    <plurals name="notify_note_new_items">
-        <item quantity="one">You received %1$d note</item>
-        <item quantity="other">You received %1$d notes</item>
-    </plurals>
-
 
     <!--Timetable-->
     <string name="timetable_lesson">Lesson</string>
@@ -97,6 +87,7 @@
     <string name="timetable_changes">Changes</string>
     <string name="timetable_no_items">No lessons this day</string>
 
+
     <!--Completed lessons-->
     <string name="completed_lessons_title">Completed lessons</string>
     <string name="completed_lessons_button">Show completed lessons</string>
@@ -105,6 +96,7 @@
     <string name="completed_lessons_absence">Absence</string>
     <string name="completed_lessons_resources">Resources</string>
 
+
     <!--Attendance-->
     <string name="attendance_summary_button">Attendance summary</string>
     <string name="attendance_absence_school">Absent for school reasons</string>
@@ -121,6 +113,7 @@
         <item quantity="other">%1$d absences</item>
     </plurals>
 
+
     <!--Attendance summary-->
     <string name="attendance_summary_final">Attendance</string>
 
@@ -145,15 +138,11 @@
         <item quantity="one">%d message</item>
         <item quantity="other">%d messages</item>
     </plurals>
-
     <plurals name="message_new_items">
         <item quantity="one">New message</item>
         <item quantity="other">New messages</item>
     </plurals>
-
-    <!--Message notify-->
-    <string name="notify_message_channel">New messages</string>
-    <plurals name="notify_message_new_items">
+    <plurals name="message_notify_new_items">
         <item quantity="one">You received %1$d message</item>
         <item quantity="other">You received %1$d messages</item>
     </plurals>
@@ -168,9 +157,6 @@
     <string name="send_message_required_recipients">You need to choose at least 1 recipient</string>
     <string name="send_message_content_min_length">The message content must be at least 3 characters</string>
 
-    <!--About-->
-    <string name="about_source_code">Source code</string>
-    <string name="about_feedback">Report a bug</string>
 
     <!--Note-->
     <string name="note_no_items">No info about notes</string>
@@ -178,25 +164,27 @@
         <item quantity="one">%d note</item>
         <item quantity="other">%d notes</item>
     </plurals>
-
     <plurals name="note_new_items">
         <item quantity="one">New note</item>
         <item quantity="other">New notes</item>
     </plurals>
+    <plurals name="note_notify_new_items">
+        <item quantity="one">You received %1$d note</item>
+        <item quantity="other">You received %1$d notes</item>
+    </plurals>
 
 
     <!--Homework-->
     <string name="homework_no_items">No info about homework</string>
 
+
     <!--Lucky number-->
     <string name="lucky_number_title">Lucky number</string>
     <string name="lucky_number_header">Today\'s lucky number is</string>
     <string name="lucky_number_empty">No info about the lucky number</string>
+    <string name="lucky_number_notify_new_item_title">Lucky number for today</string>
+    <string name="lucky_number_notify_new_item">Today\'s lucky number is: %d</string>
 
-    <!--Lucky number notify-->
-    <string name="notify_lucky_number_channel">New lucky numbers</string>
-    <string name="notify_lucky_number_new_item_title">Lucky number for today</string>
-    <string name="notify_lucky_number_new_item">Today\'s lucky number is: %d</string>
 
     <!--Account-->
     <string name="account_add_new">Add account</string>
@@ -205,6 +193,11 @@
     <string name="account_logout_student">Student logout</string>
 
 
+    <!--About-->
+    <string name="about_source_code">Source code</string>
+    <string name="about_feedback">Report a bug</string>
+
+
     <!--Generic-->
     <string name="all_content">Content</string>
     <string name="all_description">Description</string>
@@ -250,6 +243,10 @@
     <string name="pref_services_wifi">Wi-Fi only</string>
 
 
+    <!--Notification Channels-->
+    <string name="channel_new_entries">New entries in register</string>
+
+
     <!--Colors-->
     <string name="all_black">Black</string>
     <string name="all_red">Red</string>
@@ -262,6 +259,7 @@
     <!--Others-->
     <string name="all_copied">Copied</string>
 
+
     <!--Errors-->
     <string name="error_no_internet">No internet connection</string>
     <string name="error_timeout">Too long wait for connection</string>
diff --git a/app/src/test/java/io/github/wulkanowy/ui/modules/main/MainPresenterTest.kt b/app/src/test/java/io/github/wulkanowy/ui/modules/main/MainPresenterTest.kt
index 2fd6dee6..f7c5559d 100644
--- a/app/src/test/java/io/github/wulkanowy/ui/modules/main/MainPresenterTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/ui/modules/main/MainPresenterTest.kt
@@ -3,7 +3,7 @@ package io.github.wulkanowy.ui.modules.main
 import io.github.wulkanowy.TestSchedulersProvider
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
 import io.github.wulkanowy.data.repositories.student.StudentRepository
-import io.github.wulkanowy.services.job.ServiceHelper
+import io.github.wulkanowy.services.sync.SyncManager
 import io.github.wulkanowy.ui.base.ErrorHandler
 import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
 import org.junit.Before
@@ -25,7 +25,7 @@ class MainPresenterTest {
     lateinit var prefRepository: PreferencesRepository
 
     @Mock
-    lateinit var serviceHelper: ServiceHelper
+    lateinit var syncManager: SyncManager
 
     @Mock
     lateinit var mainView: MainView
@@ -40,7 +40,7 @@ class MainPresenterTest {
         MockitoAnnotations.initMocks(this)
         clearInvocations(mainView)
 
-        presenter = MainPresenter(errorHandler, studentRepository, prefRepository, TestSchedulersProvider(), serviceHelper, analytics)
+        presenter = MainPresenter(errorHandler, studentRepository, prefRepository, syncManager, TestSchedulersProvider(), analytics)
         presenter.onAttachView(mainView, -1)
     }