diff --git a/.travis.yml b/.travis.yml
index 56c648589..b32619317 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,10 +11,10 @@ cache:
     - $HOME/.gradle/caches/
     - $HOME/.gradle/wrapper/
 
-#branches:
-#  only:
-#  - master
-#  - 0.7.x
+branches:
+  only:
+  - master
+  - 0.7.x
 
 android:
  licenses:
diff --git a/app/build.gradle b/app/build.gradle
index 4b471bdcc..0e4dbd07d 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -16,8 +16,8 @@ android {
         testApplicationId "io.github.tests.wulkanowy"
         minSdkVersion 15
         targetSdkVersion 28
-        versionCode 27
-        versionName "0.7.1"
+        versionCode 28
+        versionName "0.7.2"
         multiDexEnabled true
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true
@@ -77,7 +77,7 @@ play {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
-    implementation('io.github.wulkanowy:api:0.7.1') { exclude module: "threetenbp" }
+    implementation('com.github.wulkanowy:api:master-SNAPSHOT') { exclude module: "threetenbp" }
 
     implementation "androidx.legacy:legacy-support-v4:1.0.0"
     implementation "androidx.appcompat:appcompat:1.0.2"
@@ -86,10 +86,14 @@ dependencies {
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     implementation 'androidx.multidex:multidex:2.0.1'
 
-    implementation 'com.takisoft.preferencex:preferencex:1.0.0'
+    implementation "androidx.work:work-runtime:2.0.0"
+    implementation "androidx.work:work-rxjava2:2.0.0"
 
-    implementation "android.arch.work:work-rxjava2:1.0.0"
-    implementation "android.arch.work:work-runtime:1.0.0"
+    implementation "androidx.room:room-runtime:2.1.0-alpha06"
+    implementation "androidx.room:room-rxjava2:2.1.0-alpha06"
+    kapt "androidx.room:room-compiler:2.1.0-alpha06"
+
+    implementation 'com.takisoft.preferencex:preferencex:1.0.0'
 
     implementation 'com.squareup.inject:assisted-inject-annotations-dagger2:0.3.3'
     kapt 'com.squareup.inject:assisted-inject-processor-dagger2:0.3.3'
@@ -98,17 +102,13 @@ dependencies {
     kapt "com.google.dagger:dagger-compiler:2.21"
     kapt "com.google.dagger:dagger-android-processor:2.21"
 
-    implementation "androidx.room:room-runtime:2.1.0-alpha05"
-    implementation "androidx.room:room-rxjava2:2.1.0-alpha05"
-    kapt "androidx.room:room-compiler:2.1.0-alpha05"
-
     implementation "eu.davidea:flexible-adapter:5.1.0"
     implementation "eu.davidea:flexible-adapter-ui:1.0.0"
     implementation "com.aurelhubert:ahbottomnavigation:2.3.4"
-    implementation 'com.ncapdevi:frag-nav:3.1.0'
+    implementation 'com.ncapdevi:frag-nav:3.2.0'
 
     implementation 'com.github.wulkanowy:MaterialChipsInput:b72fd0ee6f'
-    implementation 'com.github.PhilJay:MPAndroidChart:971640b29d'
+    implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
 
     implementation 'com.github.pwittchen:reactivenetwork-rx2:3.0.2'
     implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
@@ -128,15 +128,15 @@ dependencies {
     debugImplementation "com.amitshekhar.android:debug-db:1.0.6"
 
     testImplementation "junit:junit:4.12"
-    testImplementation "io.mockk:mockk:1.9.1"
-    testImplementation "org.mockito:mockito-inline:2.25.0"
+    testImplementation "io.mockk:mockk:1.9.2"
+    testImplementation "org.mockito:mockito-inline:2.25.1"
     testImplementation 'org.threeten:threetenbp:1.3.8'
 
-    androidTestImplementation "io.mockk:mockk-android:1.9.1"
     androidTestImplementation 'androidx.test:core:1.1.0'
     androidTestImplementation 'androidx.test:runner:1.1.1'
     androidTestImplementation 'androidx.test.ext:junit:1.1.0'
-    androidTestImplementation 'org.mockito:mockito-android:2.25.0'
+    androidTestImplementation "io.mockk:mockk-android:1.9.2"
+    androidTestImplementation 'org.mockito:mockito-android:2.25.1'
     androidTestImplementation "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
 }
 
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 352b6d2b6..0c6edab46 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -52,6 +52,7 @@
 
         <receiver
             android:name=".ui.widgets.timetable.TimetableWidgetProvider"
+            android:exported="true"
             android:label="@string/timetable_title">
             <intent-filter>
                 <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/SemesterDao.kt b/app/src/main/java/io/github/wulkanowy/data/db/dao/SemesterDao.kt
index 44de31d85..608a66630 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/SemesterDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/SemesterDao.kt
@@ -1,8 +1,8 @@
 package io.github.wulkanowy.data.db.dao
 
 import androidx.room.Dao
+import androidx.room.Delete
 import androidx.room.Insert
-import androidx.room.OnConflictStrategy.IGNORE
 import androidx.room.Query
 import io.github.wulkanowy.data.db.entities.Semester
 import io.reactivex.Maybe
@@ -12,15 +12,12 @@ import javax.inject.Singleton
 @Dao
 interface SemesterDao {
 
-    @Insert(onConflict = IGNORE)
+    @Insert
     fun insertAll(semester: List<Semester>)
 
+    @Delete
+    fun deleteAll(semester: List<Semester>)
+
     @Query("SELECT * FROM Semesters WHERE student_id = :studentId")
     fun loadAll(studentId: Int): Maybe<List<Semester>>
-
-    @Query("UPDATE Semesters SET is_current = 1 WHERE semester_id = :semesterId AND diary_id = :diaryId")
-    fun updateCurrent(semesterId: Int, diaryId: Int)
-
-    @Query("UPDATE Semesters SET is_current = 0 WHERE student_id = :studentId")
-    fun resetCurrent(studentId: Int)
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterLocal.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterLocal.kt
index 5be82d7f9..37d4a2687 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterLocal.kt
@@ -11,17 +11,14 @@ import javax.inject.Singleton
 class SemesterLocal @Inject constructor(private val semesterDb: SemesterDao) {
 
     fun saveSemesters(semesters: List<Semester>) {
-        return semesterDb.insertAll(semesters)
+        semesterDb.insertAll(semesters)
+    }
+
+    fun deleteSemesters(semesters: List<Semester>) {
+        semesterDb.deleteAll(semesters)
     }
 
     fun getSemesters(student: Student): Maybe<List<Semester>> {
         return semesterDb.loadAll(student.studentId).filter { !it.isEmpty() }
     }
-
-    fun setCurrentSemester(semester: Semester) {
-        semesterDb.run {
-            resetCurrent(semester.studentId)
-            updateCurrent(semester.semesterId, semester.diaryId)
-        }
-    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterRepository.kt b/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterRepository.kt
index 975868a22..9735f0290 100644
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/semester/SemesterRepository.kt
@@ -7,6 +7,7 @@ import io.github.wulkanowy.data.db.entities.Semester
 import io.github.wulkanowy.data.db.entities.Student
 import io.reactivex.Maybe
 import io.reactivex.Single
+import timber.log.Timber
 import java.net.UnknownHostException
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -25,10 +26,17 @@ class SemesterRepository @Inject constructor(
             .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
                 .flatMap {
                     if (it) remote.getSemesters(student) else Single.error(UnknownHostException())
-                }.map { newSemesters ->
-                    local.apply {
-                        saveSemesters(newSemesters)
-                        setCurrentSemester(newSemesters.single { it.isCurrent })
+                }.flatMap { new ->
+                    val currentSemesters = new.filter { it.isCurrent }
+                    if (currentSemesters.size == 1) {
+                        local.getSemesters(student).toSingle(emptyList())
+                            .doOnSuccess { old ->
+                                local.deleteSemesters(old - new)
+                                local.saveSemesters(new - old)
+                            }
+                    } else {
+                        Timber.i("Current semesters list:\n${currentSemesters.joinToString(separator = "\n")}")
+                        throw IllegalArgumentException("Current semester can be only one.")
                     }
                 }.flatMap { local.getSemesters(student).toSingle(emptyList()) })
     }
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 2616acc38..7f4776304 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.widgets.TimetableWidgetService
 import io.github.wulkanowy.ui.modules.login.LoginActivity
 import io.github.wulkanowy.ui.modules.login.LoginModule
 import io.github.wulkanowy.ui.modules.main.MainActivity
@@ -30,9 +29,6 @@ internal abstract class BuilderModule {
     @ContributesAndroidInjector
     abstract fun bindMessageSendActivity(): SendMessageActivity
 
-    @ContributesAndroidInjector
-    abstract fun bindTimetableWidgetService(): TimetableWidgetService
-
     @ContributesAndroidInjector
     abstract fun bindTimetableWidgetProvider(): TimetableWidgetProvider
 }
diff --git a/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt b/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt
index 70cbf84c8..84409a845 100644
--- a/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/services/ServicesModule.kt
@@ -9,6 +9,7 @@ import com.squareup.inject.assisted.dagger2.AssistedModule
 import dagger.Binds
 import dagger.Module
 import dagger.Provides
+import dagger.android.ContributesAndroidInjector
 import dagger.multibindings.IntoSet
 import io.github.wulkanowy.services.sync.works.AttendanceSummaryWork
 import io.github.wulkanowy.services.sync.works.AttendanceWork
@@ -24,6 +25,7 @@ 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 io.github.wulkanowy.services.widgets.TimetableWidgetService
 import javax.inject.Singleton
 
 @AssistedModule
@@ -48,6 +50,9 @@ abstract class ServicesModule {
         fun provideNotificationManager(context: Context) = context.getSystemService(NOTIFICATION_SERVICE) as NotificationManager
     }
 
+    @ContributesAndroidInjector
+    abstract fun bindTimetableWidgetService(): TimetableWidgetService
+
     @Binds
     @IntoSet
     abstract fun provideGradeWork(work: GradeWork): Work
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
index ec753b7e2..365939664 100644
--- a/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorker.kt
+++ b/app/src/main/java/io/github/wulkanowy/services/sync/SyncWorker.kt
@@ -11,6 +11,7 @@ import androidx.work.WorkerParameters
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
 import io.github.wulkanowy.R
+import io.github.wulkanowy.api.interceptor.FeatureDisabledException
 import io.github.wulkanowy.data.repositories.preferences.PreferencesRepository
 import io.github.wulkanowy.data.repositories.semester.SemesterRepository
 import io.github.wulkanowy.data.repositories.student.StudentRepository
@@ -18,6 +19,7 @@ import io.github.wulkanowy.services.sync.channels.DebugChannel
 import io.github.wulkanowy.services.sync.works.Work
 import io.github.wulkanowy.utils.getCompatColor
 import io.reactivex.Completable
+import io.reactivex.Flowable
 import io.reactivex.Single
 import timber.log.Timber
 import kotlin.random.Random
@@ -33,19 +35,31 @@ class SyncWorker @AssistedInject constructor(
 ) : RxWorker(appContext, workerParameters) {
 
     override fun createWork(): Single<Result> {
-        return studentRepository.getCurrentStudent()
+        Timber.i("SyncWorker is starting")
+        return studentRepository.isStudentSaved()
+            .filter { true }
+            .flatMap { studentRepository.getCurrentStudent().toMaybe() }
             .flatMapCompletable { student ->
                 semesterRepository.getCurrentSemester(student, true)
                     .flatMapCompletable { semester ->
-                        Completable.mergeDelayError(works.map { it.create(student, semester) })
+                        Completable.mergeDelayError(Flowable.fromIterable(works.map { work ->
+                            work.create(student, semester)
+                                .doOnSubscribe { Timber.i("${work::class.java.simpleName} is starting") }
+                                .doOnError { Timber.i("${work::class.java.simpleName} result: An exception occurred") }
+                                .doOnComplete { Timber.i("${work::class.java.simpleName} result: Success") }
+                        }), 3)
                     }
             }
             .toSingleDefault(Result.success())
             .onErrorReturn {
                 Timber.e(it, "There was an error during synchronization")
-                Result.retry()
+                if (it is FeatureDisabledException) Result.success()
+                else Result.retry()
+            }
+            .doOnSuccess {
+                if (preferencesRepository.isDebugNotificationEnable) notify(it)
+                Timber.i("SyncWorker result: $it")
             }
-            .doOnSuccess { if (preferencesRepository.isDebugNotificationEnable) notify(it) }
     }
 
     private fun notify(result: Result) {
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
index af8de4348..fa610dee4 100644
--- 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
@@ -13,10 +13,10 @@ class RecipientWork @Inject constructor(
 ) : Work {
 
     override fun create(student: Student, semester: Semester): Completable {
-        return reportingUnitRepository.getReportingUnits(student)
+        return reportingUnitRepository.getReportingUnits(student, true)
             .flatMapCompletable { units ->
                 Completable.mergeDelayError(units.map {
-                    recipientRepository.getRecipients(student, 2, it).ignoreElement()
+                    recipientRepository.getRecipients(student, 2, it, true).ignoreElement()
                 })
             }
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/about/AboutFragment.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/about/AboutFragment.kt
index 1002f914f..52caf731e 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/about/AboutFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/about/AboutFragment.kt
@@ -43,7 +43,8 @@ class AboutFragment : BaseFragment(), AboutView, MainView.TitledView {
                 .withAboutSpecial3(getString(R.string.about_feedback))
                 .withFields(R.string::class.java.fields)
                 .withCheckCachedDetection(false)
-                .withExcludedLibraries("fastadapter", "AndroidIconics", "gson", "Jsoup", "Retrofit", "okio", "OkHttp")
+                .withExcludedLibraries("fastadapter", "AndroidIconics", "Jsoup", "Retrofit", "okio",
+                    "OkHttp", "Butterknife", "CircleImageView")
                 .withOnExtraListener { presenter.onExtraSelect(it) })
         }.let {
             fragmentCompat.onCreateView(inflater.context, inflater, container, savedInstanceState, it)
@@ -68,7 +69,7 @@ class AboutFragment : BaseFragment(), AboutView, MainView.TitledView {
             data = Uri.parse("mailto:")
             putExtra(Intent.EXTRA_EMAIL, Array(1) { "wulkanowyinc@gmail.com" })
             putExtra(Intent.EXTRA_SUBJECT, "Zgłoszenie błędu")
-            putExtra(Intent.EXTRA_TEXT,"Tu umieść treść zgłoszenia\n\n" + "-".repeat(40) + "\n" + """
+            putExtra(Intent.EXTRA_TEXT, "Tu umieść treść zgłoszenia\n\n" + "-".repeat(40) + "\n" + """
                 Build: ${BuildConfig.VERSION_CODE}
                 SDK: ${android.os.Build.VERSION.SDK_INT}
                 Device: ${android.os.Build.MANUFACTURER} ${android.os.Build.MODEL}
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountItem.kt
index a564306d5..cb7aabda7 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/account/AccountItem.kt
@@ -14,12 +14,12 @@ class AccountItem(val student: Student) : AbstractFlexibleItem<AccountItem.ViewH
 
     override fun getLayoutRes() = R.layout.item_account
 
-    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?): ViewHolder {
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>?, holder: ViewHolder?, position: Int, payloads: MutableList<Any>?) {
-        holder?.apply {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
+        holder.apply {
             accountItemName.text = student.studentName
             accountItemSchool.text = student.schoolName
             accountItemImage.setBackgroundResource(if (student.isCurrent) R.drawable.ic_account_circular_border else 0)
@@ -38,14 +38,13 @@ class AccountItem(val student: Student) : AbstractFlexibleItem<AccountItem.ViewH
     }
 
     override fun hashCode(): Int {
-        return student.hashCode()
+        var result = student.hashCode()
+        result = 31 * result + student.id.toInt()
+        return result
     }
 
-    class ViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
-        override val containerView: View?
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
+        override val containerView: View
             get() = contentView
     }
 }
-
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceItem.kt
index c2698ebba..16a140cbf 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendanceItem.kt
@@ -14,14 +14,13 @@ import kotlinx.android.synthetic.main.item_attendance.*
 
 class AttendanceItem(val attendance: Attendance) : AbstractFlexibleItem<AttendanceItem.ViewHolder>() {
 
+    override fun getLayoutRes() = R.layout.item_attendance
+
     override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
-    override fun getLayoutRes(): Int = R.layout.item_attendance
-
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-                                position: Int, payloads: MutableList<Any>?) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.apply {
             attendanceItemNumber.text = attendance.number.toString()
             attendanceItemSubject.text = attendance.subject
@@ -37,16 +36,17 @@ class AttendanceItem(val attendance: Attendance) : AbstractFlexibleItem<Attendan
         other as AttendanceItem
 
         if (attendance != other.attendance) return false
+
         return true
     }
 
     override fun hashCode(): Int {
-        return attendance.hashCode()
+        var result = attendance.hashCode()
+        result = 31 * result + attendance.id.toInt()
+        return result
     }
 
-    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-            LayoutContainer {
-
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendancePresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendancePresenter.kt
index 988681b1e..ec471c16a 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendancePresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/AttendancePresenter.kt
@@ -135,7 +135,7 @@ class AttendancePresenter @Inject constructor(
             clearData()
             showNextButton(!currentDate.plusDays(1).isHolidays)
             showPreButton(!currentDate.minusDays(1).isHolidays)
-            updateNavigationDay(currentDate.toFormattedString("EEEE \n dd.MM.YYYY").capitalize())
+            updateNavigationDay(currentDate.toFormattedString("EEEE\ndd.MM.YYYY").capitalize())
         }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryItem.kt
index 3102ce116..265d6ce44 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryItem.kt
@@ -23,12 +23,12 @@ class AttendanceSummaryItem(
 
     override fun getLayoutRes() = R.layout.item_attendance_summary
 
-    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?): ViewHolder {
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>?, holder: ViewHolder?, position: Int, payloads: MutableList<Any>?) {
-        holder?.apply {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
+        holder.apply {
             attendanceSummaryMonth.text = month
             attendanceSummaryPercentage.text = percentage
             attendanceSummaryPresent.text = present
@@ -73,10 +73,8 @@ class AttendanceSummaryItem(
         return result
     }
 
-    class ViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
-        override val containerView: View?
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
+        override val containerView: View
             get() = contentView
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamItem.kt
index 318685e93..8971b4df3 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/exam/ExamItem.kt
@@ -18,8 +18,7 @@ class ExamItem(header: ExamHeader, val exam: Exam) : AbstractSectionableItem<Exa
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-                                position: Int, payloads: MutableList<Any>?) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.run {
             examItemSubject.text = exam.subject
             examItemTeacher.text = exam.teacher
@@ -39,12 +38,12 @@ class ExamItem(header: ExamHeader, val exam: Exam) : AbstractSectionableItem<Exa
     }
 
     override fun hashCode(): Int {
-        return exam.hashCode()
+        var result = exam.hashCode()
+        result = 31 * result + exam.id.toInt()
+        return result
     }
 
-    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-            LayoutContainer {
-
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt
index 98eb2a9f4..2357e0637 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt
@@ -7,9 +7,7 @@ import io.github.wulkanowy.ui.base.session.BaseSessionPresenter
 import io.github.wulkanowy.ui.base.session.SessionErrorHandler
 import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
 import io.github.wulkanowy.utils.SchedulersProvider
-import io.reactivex.Completable
 import timber.log.Timber
-import java.util.concurrent.TimeUnit.MILLISECONDS
 import javax.inject.Inject
 
 class GradePresenter @Inject constructor(
@@ -30,15 +28,12 @@ class GradePresenter @Inject constructor(
     fun onAttachView(view: GradeView, savedIndex: Int?) {
         super.onAttachView(view)
         Timber.i("Grade view is attached")
-        disposable.add(Completable.timer(150, MILLISECONDS, schedulers.mainThread)
-            .subscribe {
-                selectedIndex = savedIndex ?: 0
-                view.run {
-                    initView()
-                    enableSwipe(false)
-                }
-                loadData()
-            })
+        selectedIndex = savedIndex ?: 0
+        view.run {
+            initView()
+            enableSwipe(false)
+        }
+        loadData()
     }
 
     fun onCreateMenu() {
@@ -82,7 +77,7 @@ class GradePresenter @Inject constructor(
     }
 
     fun onPageSelected(index: Int) {
-        loadChild(index)
+        if (semesters.isNotEmpty()) loadChild(index)
     }
 
     fun onSwipeRefresh() {
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsItem.kt
index de1d88f7d..1e47eca5d 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsItem.kt
@@ -28,10 +28,7 @@ class GradeDetailsItem(
     }
 
     @SuppressLint("SetTextI18n")
-    override fun bindViewHolder(
-        adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-        position: Int, payloads: MutableList<Any>?
-    ) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.run {
             gradeItemValue.run {
                 text = grade.entry
@@ -70,9 +67,7 @@ class GradeDetailsItem(
         return result
     }
 
-    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt
index 5111420d2..5dd485cd5 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt
@@ -63,7 +63,7 @@ class GradeStatisticsPresenter @Inject constructor(
     }
 
     fun onSubjectSelected(name: String) {
-        Timber.i("Select attendance stats subject $name")
+        Timber.i("Select grade stats subject $name")
         view?.run {
             showContent(false)
             showProgress(true)
@@ -77,7 +77,7 @@ class GradeStatisticsPresenter @Inject constructor(
     }
 
     fun onTypeChange(isSemester: Boolean) {
-        Timber.i("Select attendance stats semester: $isSemester")
+        Timber.i("Select grade stats semester: $isSemester")
         disposable.clear()
         view?.run {
             showContent(false)
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryItem.kt
index 0daf06657..5737a832f 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryItem.kt
@@ -18,15 +18,12 @@ class GradeSummaryItem(
 
     override fun getLayoutRes() = R.layout.item_grade_summary
 
-    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?): ViewHolder {
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(
-        adapter: FlexibleAdapter<IFlexible<*>>?, holder: ViewHolder?,
-        position: Int, payloads: MutableList<Any>?
-    ) {
-        holder?.run {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
+        holder.run {
             gradeSummaryItemTitle.text = title
             gradeSummaryItemAverage.text = average
             gradeSummaryItemPredicted.text = predictedGrade
@@ -56,10 +53,8 @@ class GradeSummaryItem(
         return result
     }
 
-    class ViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
-        override val containerView: View?
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
+        override val containerView: View
             get() = contentView
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkItem.kt
index a2b8cc0a7..2de9233f2 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/homework/HomeworkItem.kt
@@ -10,9 +10,8 @@ import io.github.wulkanowy.data.db.entities.Homework
 import kotlinx.android.extensions.LayoutContainer
 import kotlinx.android.synthetic.main.item_homework.*
 
-class HomeworkItem(
-    header: HomeworkHeader, val homework: Homework
-) : AbstractSectionableItem<HomeworkItem.ViewHolder, HomeworkHeader>(header) {
+class HomeworkItem(header: HomeworkHeader, val homework: Homework) :
+    AbstractSectionableItem<HomeworkItem.ViewHolder, HomeworkHeader>(header) {
 
     override fun getLayoutRes() = R.layout.item_homework
 
@@ -20,10 +19,7 @@ class HomeworkItem(
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(
-        adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-        position: Int, payloads: MutableList<Any>?
-    ) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.apply {
             homeworkItemSubject.text = homework.subject
             homeworkItemTeacher.text = homework.teacher
@@ -42,12 +38,12 @@ class HomeworkItem(
     }
 
     override fun hashCode(): Int {
-        return homework.hashCode()
+        var result = homework.hashCode()
+        result = 31 * result + homework.id.toInt()
+        return result
     }
 
-    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
+    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectItem.kt
index c206a499d..71a7d681e 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectItem.kt
@@ -8,19 +8,21 @@ import eu.davidea.viewholders.FlexibleViewHolder
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Student
 import kotlinx.android.extensions.LayoutContainer
-import kotlinx.android.synthetic.main.item_login_student_select.view.*
+import kotlinx.android.synthetic.main.item_login_student_select.*
 
 class LoginStudentSelectItem(val student: Student) : AbstractFlexibleItem<LoginStudentSelectItem.ItemViewHolder>() {
 
     override fun getLayoutRes(): Int = R.layout.item_login_student_select
 
-    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?): ItemViewHolder {
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ItemViewHolder {
         return ItemViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>?, holder: ItemViewHolder?,
-                                position: Int, payloads: MutableList<Any>?) {
-        holder?.bind(student)
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ItemViewHolder, position: Int, payloads: MutableList<Any>?) {
+        holder.run {
+            loginItemName.text = student.studentName
+            loginItemSchool.text = student.schoolName
+        }
     }
 
     override fun equals(other: Any?): Boolean {
@@ -38,17 +40,8 @@ class LoginStudentSelectItem(val student: Student) : AbstractFlexibleItem<LoginS
         return student.hashCode()
     }
 
-    class ItemViewHolder(view: View?, adapter: FlexibleAdapter<*>?)
-        : FlexibleViewHolder(view, adapter), LayoutContainer {
-
-        override val containerView: View?
+    class ItemViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
+        override val containerView: View
             get() = itemView
-
-        fun bind(item: Student) {
-            itemView.run {
-                loginItemName.text = item.studentName
-                loginItemSchool.text = item.schoolName
-            }
-        }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberPresenter.kt
index 92ee4e250..74ab0d1fe 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/luckynumber/LuckyNumberPresenter.kt
@@ -22,7 +22,11 @@ class LuckyNumberPresenter @Inject constructor(
     override fun onAttachView(view: LuckyNumberView) {
         super.onAttachView(view)
         Timber.i("Lucky number view is attached")
-        view.initView()
+        view.run {
+            initView()
+            showContent(false)
+            enableSwipe(false)
+        }
         loadData()
     }
 
@@ -35,12 +39,6 @@ class LuckyNumberPresenter @Inject constructor(
                 .flatMapMaybe { luckyNumberRepository.getLuckyNumber(it, forceRefresh) }
                 .subscribeOn(schedulers.backgroundThread)
                 .observeOn(schedulers.mainThread)
-                .doOnSubscribe {
-                    view?.run {
-                        showContent(false)
-                        enableSwipe(false)
-                    }
-                }
                 .doFinally {
                     view?.run {
                         hideRefresh()
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 5e0ed2b2f..4448e556b 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
@@ -2,7 +2,10 @@ package io.github.wulkanowy.ui.modules.main
 
 import android.content.Context
 import android.content.Intent
+import android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK
+import android.content.Intent.FLAG_ACTIVITY_NEW_TASK
 import android.os.Bundle
+import android.os.Handler
 import android.view.Menu
 import android.view.MenuItem
 import androidx.appcompat.app.AlertDialog
@@ -68,11 +71,6 @@ class MainActivity : BaseActivity(), MainView {
         return true
     }
 
-    override fun onStart() {
-        super.onStart()
-        presenter.onViewChange()
-    }
-
     override fun initView() {
         mainBottomNav.run {
             addItems(
@@ -144,7 +142,9 @@ class MainActivity : BaseActivity(), MainView {
     }
 
     override fun notifyMenuViewReselected() {
-        (navController.currentStack?.get(0) as? MainView.MainChildView)?.onFragmentReselected()
+        Handler().postDelayed({
+            (navController.currentStack?.get(0) as? MainView.MainChildView)?.onFragmentReselected()
+        }, 250)
     }
 
     fun showDialogFragment(dialog: DialogFragment) {
@@ -165,7 +165,7 @@ class MainActivity : BaseActivity(), MainView {
 
     override fun openLoginView() {
         startActivity(LoginActivity.getStartIntent(this)
-            .apply { addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK) })
+            .apply { addFlags(FLAG_ACTIVITY_CLEAR_TASK or FLAG_ACTIVITY_NEW_TASK) })
     }
 
     override fun onSaveInstanceState(outState: Bundle?) {
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt
index d1afd9c02..de4405b74 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt
@@ -5,7 +5,6 @@ import dagger.Module
 import dagger.Provides
 import dagger.android.ContributesAndroidInjector
 import io.github.wulkanowy.R
-import io.github.wulkanowy.di.scopes.PerActivity
 import io.github.wulkanowy.di.scopes.PerFragment
 import io.github.wulkanowy.ui.modules.about.AboutFragment
 import io.github.wulkanowy.ui.modules.about.AboutModule
@@ -33,7 +32,6 @@ abstract class MainModule {
     companion object {
 
         @JvmStatic
-        @PerActivity
         @Provides
         fun provideFragNavController(activity: MainActivity): FragNavController {
             return FragNavController(activity.supportFragmentManager, R.id.mainFragmentContainer)
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 a2a973c64..30f3b920f 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
@@ -24,9 +24,9 @@ class MainPresenter @Inject constructor(
 
     fun onAttachView(view: MainView, initMenuIndex: Int) {
         super.onAttachView(view)
-        Timber.i("Main view is attached with $initMenuIndex menu index")
         view.run {
             startMenuIndex = if (initMenuIndex != -1) initMenuIndex else prefRepository.startMenuIndex
+            Timber.i("Main view is attached with $startMenuIndex menu index")
             initView()
         }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt
index ec725a386..26568e22f 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt
@@ -20,12 +20,9 @@ class MessageItem(val message: Message, private val noSubjectString: String) :
         return ViewHolder(view, adapter)
     }
 
-    override fun getLayoutRes(): Int = R.layout.item_message
+    override fun getLayoutRes() = R.layout.item_message
 
-    override fun bindViewHolder(
-        adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-        position: Int, payloads: MutableList<Any>?
-    ) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.apply {
             val style = if (message.unread) BOLD else NORMAL
 
@@ -58,9 +55,7 @@ class MessageItem(val message: Message, private val noSubjectString: String) :
         return message.hashCode()
     }
 
-    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-        LayoutContainer {
-
+    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreItem.kt
index e8571a8c6..85b604e77 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreItem.kt
@@ -14,12 +14,12 @@ class MoreItem(val title: String, private val drawable: Drawable?) : AbstractFle
 
     override fun getLayoutRes() = R.layout.item_more
 
-    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<*>>?): ViewHolder {
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>?, holder: ViewHolder?, position: Int, payloads: MutableList<Any>?) {
-        holder?.apply {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
+        holder.apply {
             moreItemTitle.text = title
             moreItemImage.setImageDrawable(drawable)
         }
@@ -40,9 +40,8 @@ class MoreItem(val title: String, private val drawable: Drawable?) : AbstractFle
         return title.hashCode()
     }
 
-    class ViewHolder(view: View?, adapter: FlexibleAdapter<*>?) : FlexibleViewHolder(view, adapter), LayoutContainer {
-
-        override val containerView: View?
+    class ViewHolder(view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
+        override val containerView: View
             get() = contentView
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteItem.kt
index 71562fc49..dabeef74a 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/note/NoteItem.kt
@@ -15,16 +15,13 @@ import kotlinx.android.synthetic.main.item_note.*
 
 class NoteItem(val note: Note) : AbstractFlexibleItem<NoteItem.ViewHolder>() {
 
+    override fun getLayoutRes() = R.layout.item_note
+
     override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): NoteItem.ViewHolder {
         return NoteItem.ViewHolder(view, adapter)
     }
 
-    override fun getLayoutRes(): Int = R.layout.item_note
-
-    override fun bindViewHolder(
-        adapter: FlexibleAdapter<IFlexible<*>>,
-        holder: NoteItem.ViewHolder, position: Int, payloads: MutableList<Any>?
-    ) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: NoteItem.ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.apply {
             noteItemDate.apply {
                 text = note.date.toFormattedString()
@@ -57,7 +54,6 @@ class NoteItem(val note: Note) : AbstractFlexibleItem<NoteItem.ViewHolder>() {
     }
 
     class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
-
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableItem.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableItem.kt
index f37c0f515..c721401f3 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetableItem.kt
@@ -15,18 +15,17 @@ import io.github.wulkanowy.utils.toFormattedString
 import kotlinx.android.extensions.LayoutContainer
 import kotlinx.android.synthetic.main.item_timetable.*
 
-class TimetableItem(val lesson: Timetable, private val roomText: String)
-    : AbstractFlexibleItem<TimetableItem.ViewHolder>() {
+class TimetableItem(val lesson: Timetable, private val roomText: String) :
+    AbstractFlexibleItem<TimetableItem.ViewHolder>() {
 
-    override fun getLayoutRes(): Int = R.layout.item_timetable
+    override fun getLayoutRes() = R.layout.item_timetable
 
     override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
         return ViewHolder(view, adapter)
     }
 
     @SuppressLint("SetTextI18n")
-    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
-                                position: Int, payloads: MutableList<Any>?) {
+    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
         holder.apply {
             timetableItemNumber.text = lesson.number.toString()
             timetableItemSubject.text = lesson.subject
@@ -34,8 +33,8 @@ class TimetableItem(val lesson: Timetable, private val roomText: String)
             timetableItemTime.text = "${lesson.start.toFormattedString("HH:mm")} - ${lesson.end.toFormattedString("HH:mm")}"
             timetableItemAlert.visibility = if (lesson.changes || lesson.canceled) VISIBLE else GONE
             timetableItemSubject.paintFlags =
-                    if (lesson.canceled) timetableItemSubject.paintFlags or Paint.STRIKE_THRU_TEXT_FLAG
-                    else timetableItemSubject.paintFlags and Paint.STRIKE_THRU_TEXT_FLAG.inv()
+                if (lesson.canceled) timetableItemSubject.paintFlags or Paint.STRIKE_THRU_TEXT_FLAG
+                else timetableItemSubject.paintFlags and Paint.STRIKE_THRU_TEXT_FLAG.inv()
         }
     }
 
@@ -50,12 +49,12 @@ class TimetableItem(val lesson: Timetable, private val roomText: String)
     }
 
     override fun hashCode(): Int {
-        return lesson.hashCode()
+        var result = lesson.hashCode()
+        result = 31 * result + lesson.id.toInt()
+        return result
     }
 
-    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
-            LayoutContainer {
-
+    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter), LayoutContainer {
         override val containerView: View
             get() = contentView
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetablePresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetablePresenter.kt
index 3786a362c..ebda3931a 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetablePresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/TimetablePresenter.kt
@@ -128,7 +128,7 @@ class TimetablePresenter @Inject constructor(
             clearData()
             showNextButton(!currentDate.plusDays(1).isHolidays)
             showPreButton(!currentDate.minusDays(1).isHolidays)
-            updateNavigationDay(currentDate.toFormattedString("EEEE \n dd.MM.YYYY").capitalize())
+            updateNavigationDay(currentDate.toFormattedString("EEEE\ndd.MM.YYYY").capitalize())
         }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsPresenter.kt
index ddc81818f..6a14acda5 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/timetable/completed/CompletedLessonsPresenter.kt
@@ -112,7 +112,7 @@ class CompletedLessonsPresenter @Inject constructor(
             clearData()
             showNextButton(!currentDate.plusDays(1).isHolidays)
             showPreButton(!currentDate.minusDays(1).isHolidays)
-            updateNavigationDay(currentDate.toFormattedString("EEEE \n dd.MM.YYYY").capitalize())
+            updateNavigationDay(currentDate.toFormattedString("EEEE\ndd.MM.YYYY").capitalize())
         }
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetFactory.kt b/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetFactory.kt
index 63560807c..f2d40ba7e 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetFactory.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetFactory.kt
@@ -17,6 +17,7 @@ import io.github.wulkanowy.data.repositories.student.StudentRepository
 import io.github.wulkanowy.data.repositories.timetable.TimetableRepository
 import io.github.wulkanowy.utils.SchedulersProvider
 import io.github.wulkanowy.utils.toFormattedString
+import io.reactivex.Single
 import org.threeten.bp.LocalDate
 import timber.log.Timber
 
@@ -51,9 +52,13 @@ class TimetableWidgetFactory(
             ?.let { date ->
                 try {
                     lessons = studentRepository.isStudentSaved()
-                        .flatMap { studentRepository.getCurrentStudent() }
-                        .flatMap { semesterRepository.getCurrentSemester(it) }
-                        .flatMap { timetableRepository.getTimetable(it, date, date) }
+                        .flatMap { isSaved ->
+                            if (isSaved) {
+                                studentRepository.getCurrentStudent()
+                                    .flatMap { semesterRepository.getCurrentSemester(it) }
+                                    .flatMap { timetableRepository.getTimetable(it, date, date) }
+                            } else Single.just(emptyList())
+                        }
                         .map { item -> item.sortedBy { it.number } }
                         .subscribeOn(schedulers.backgroundThread)
                         .blockingGet()
diff --git a/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetProvider.kt b/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetProvider.kt
index 290007e44..402366ecf 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetProvider.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/widgets/timetable/TimetableWidgetProvider.kt
@@ -62,7 +62,7 @@ class TimetableWidgetProvider : BroadcastReceiver() {
 
     private fun onUpdate(context: Context, intent: Intent) {
         if (intent.getStringExtra(EXTRA_BUTTON_TYPE) === null) {
-            intent.getIntArrayExtra(EXTRA_APPWIDGET_IDS).forEach { appWidgetId ->
+            intent.getIntArrayExtra(EXTRA_APPWIDGET_IDS)?.forEach { appWidgetId ->
                 updateWidget(context, appWidgetId, now().nextOrSameSchoolDay)
             }
         } else {
@@ -95,7 +95,7 @@ class TimetableWidgetProvider : BroadcastReceiver() {
                 .apply { action = createWidgetKey(appWidgetId) })
             setOnClickPendingIntent(R.id.timetableWidgetNext, createNavIntent(context, appWidgetId, appWidgetId, BUTTON_NEXT))
             setOnClickPendingIntent(R.id.timetableWidgetPrev, createNavIntent(context, -appWidgetId, appWidgetId, BUTTON_PREV))
-            createNavIntent(context, Int.MAX_VALUE, appWidgetId, BUTTON_RESET).also {
+            createNavIntent(context, Int.MAX_VALUE - appWidgetId, appWidgetId, BUTTON_RESET).also {
                 setOnClickPendingIntent(R.id.timetableWidgetDate, it)
                 setOnClickPendingIntent(R.id.timetableWidgetDay, it)
             }
diff --git a/app/src/main/play/release-notes/pl-PL/default.txt b/app/src/main/play/release-notes/pl-PL/default.txt
index 6f8a6b0a1..bdf045f52 100644
--- a/app/src/main/play/release-notes/pl-PL/default.txt
+++ b/app/src/main/play/release-notes/pl-PL/default.txt
@@ -1,18 +1,6 @@
-Dodaliśmy:
-- szczęśliwy numerek
-- lekcje zrealizowane
-- wysyłanie wiadomości
-- ucznia na tle klasy
-- opcję zmiany kolorów ocen
-
-Zmieniliśmy:
-- wygląd ekranu logowania
-- sposób wyświetlania zastępstw
-- widok zadań domowych na tygodniowy
-
 Naprawiliśmy:
-- automatyczne przełączanie widżetu na nowy dzień
-- wyświetlanie powiadomień o starych ocenach
-- znikające numery sal w planie lekcji
+- problemy ze stabilnością podczas przełączania zakładek
+- nierówność w nawigacji między dniami w planie lekcji i frekwencji
+- zły wygląd odświeżania w szczęśliwym numerku
 
-Pełna lista zmian: https://github.com/wulkanowy/wulkanowy/releases/tag/0.7.0
+Pełna lista zmian: https://github.com/wulkanowy/wulkanowy/releases/tag/0.7.2
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/UnitTestInternetObservingStrategy.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/UnitTestInternetObservingStrategy.kt
new file mode 100644
index 000000000..28abbb993
--- /dev/null
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/UnitTestInternetObservingStrategy.kt
@@ -0,0 +1,19 @@
+package io.github.wulkanowy.data.repositories
+
+import com.github.pwittchen.reactivenetwork.library.rx2.internet.observing.InternetObservingStrategy
+import com.github.pwittchen.reactivenetwork.library.rx2.internet.observing.error.ErrorHandler
+import io.reactivex.Observable
+import io.reactivex.Single
+
+class UnitTestInternetObservingStrategy : InternetObservingStrategy {
+
+    override fun checkInternetConnectivity(host: String?, port: Int, timeoutInMs: Int, httpResponse: Int, errorHandler: ErrorHandler?): Single<Boolean> {
+        return Single.just(true)
+    }
+
+    override fun observeInternetConnectivity(initialIntervalInMs: Int, intervalInMs: Int, host: String?, port: Int, timeoutInMs: Int, httpResponse: Int, errorHandler: ErrorHandler?): Observable<Boolean> {
+        return Observable.just(true)
+    }
+
+    override fun getDefaultPingHost() = "localhost"
+}
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/AttendanceRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/attendance/AttendanceRemoteTest.kt
similarity index 92%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/AttendanceRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/attendance/AttendanceRemoteTest.kt
index 4842d305c..8adfa83bd 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/AttendanceRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/attendance/AttendanceRemoteTest.kt
@@ -1,9 +1,8 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.attendance
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.attendance.Attendance
 import io.github.wulkanowy.data.db.entities.Semester
-import io.github.wulkanowy.data.repositories.attendance.AttendanceRemote
 import io.mockk.MockKAnnotations
 import io.mockk.every
 import io.mockk.impl.annotations.MockK
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/CompletedLessonsRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsRemoteTest.kt
similarity index 91%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/CompletedLessonsRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsRemoteTest.kt
index f4c161bc4..bb9f52945 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/CompletedLessonsRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/completedlessons/CompletedLessonsRemoteTest.kt
@@ -1,9 +1,8 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.completedlessons
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.timetable.CompletedLesson
 import io.github.wulkanowy.data.db.entities.Semester
-import io.github.wulkanowy.data.repositories.completedlessons.CompletedLessonsRemote
 import io.mockk.MockKAnnotations
 import io.mockk.every
 import io.mockk.impl.annotations.MockK
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/ExamRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/exam/ExamRemoteTest.kt
similarity index 93%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/ExamRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/exam/ExamRemoteTest.kt
index 0cc785482..0c83bed0a 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/ExamRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/exam/ExamRemoteTest.kt
@@ -1,9 +1,8 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.exam
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.exams.Exam
 import io.github.wulkanowy.data.db.entities.Semester
-import io.github.wulkanowy.data.repositories.exam.ExamRemote
 import io.mockk.MockKAnnotations
 import io.mockk.every
 import io.mockk.impl.annotations.MockK
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/GradeStatisticsRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsRemoteTest.kt
similarity index 91%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/GradeStatisticsRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsRemoteTest.kt
index 14381791d..37d3f2ad6 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/GradeStatisticsRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsRemoteTest.kt
@@ -1,9 +1,8 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.gradestatistics
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.grades.GradeStatistics
 import io.github.wulkanowy.data.db.entities.Semester
-import io.github.wulkanowy.data.repositories.gradestatistics.GradeStatisticsRemote
 import io.mockk.MockKAnnotations
 import io.mockk.every
 import io.mockk.impl.annotations.MockK
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/LuckyNumberRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRemoteTest.kt
similarity index 95%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/LuckyNumberRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRemoteTest.kt
index 054f8890d..67e6c2ef6 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/LuckyNumberRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/luckynumber/LuckyNumberRemoteTest.kt
@@ -1,4 +1,4 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.luckynumber
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.data.db.entities.Semester
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/semester/SemesterRepositoryTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/semester/SemesterRepositoryTest.kt
new file mode 100644
index 000000000..7856b9370
--- /dev/null
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/semester/SemesterRepositoryTest.kt
@@ -0,0 +1,74 @@
+package io.github.wulkanowy.data.repositories.semester
+
+import com.github.pwittchen.reactivenetwork.library.rx2.internet.observing.InternetObservingSettings
+import io.github.wulkanowy.data.ApiHelper
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.UnitTestInternetObservingStrategy
+import io.reactivex.Maybe
+import io.reactivex.Single
+import org.junit.Before
+import org.junit.Test
+import org.mockito.Mock
+import org.mockito.Mockito.doNothing
+import org.mockito.Mockito.doReturn
+import org.mockito.Mockito.verify
+import org.mockito.MockitoAnnotations
+
+class SemesterRepositoryTest {
+
+    @Mock
+    private lateinit var semesterRemote: SemesterRemote
+
+    @Mock
+    private lateinit var semesterLocal: SemesterLocal
+
+    @Mock
+    private lateinit var apiHelper: ApiHelper
+
+    @Mock
+    private lateinit var student: Student
+
+    private lateinit var semesterRepository: SemesterRepository
+
+    private val settings = InternetObservingSettings.builder()
+        .strategy(UnitTestInternetObservingStrategy())
+        .build()
+
+    @Before
+    fun initTest() {
+        MockitoAnnotations.initMocks(this)
+        semesterRepository = SemesterRepository(semesterRemote, semesterLocal, settings, apiHelper)
+    }
+
+    @Test
+    fun singleCurrentSemesterTest() {
+        val semesters = listOf(
+            createSemesterEntity(false),
+            createSemesterEntity(true)
+        )
+
+        doNothing().`when`(apiHelper).initApi(student)
+        doReturn(Maybe.empty<Semester>()).`when`(semesterLocal).getSemesters(student)
+        doReturn(Single.just(semesters)).`when`(semesterRemote).getSemesters(student)
+
+        semesterRepository.getSemesters(student).blockingGet()
+
+        verify(semesterLocal).deleteSemesters(emptyList())
+        verify(semesterLocal).saveSemesters(semesters)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun twoCurrentSemesterTest() {
+        val semesters = listOf(
+            createSemesterEntity(true),
+            createSemesterEntity(true)
+        )
+
+        doNothing().`when`(apiHelper).initApi(student)
+        doReturn(Maybe.empty<Semester>()).`when`(semesterLocal).getSemesters(student)
+        doReturn(Single.just(semesters)).`when`(semesterRemote).getSemesters(student)
+
+        semesterRepository.getSemesters(student).blockingGet()
+    }
+}
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/semester/TestSemesterEnityCreator.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/semester/TestSemesterEnityCreator.kt
new file mode 100644
index 000000000..c3377ac51
--- /dev/null
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/semester/TestSemesterEnityCreator.kt
@@ -0,0 +1,16 @@
+package io.github.wulkanowy.data.repositories.semester
+
+import io.github.wulkanowy.data.db.entities.Semester
+
+fun createSemesterEntity(current: Boolean): Semester {
+    return Semester(
+        studentId = 0,
+        diaryId = 0,
+        semesterId = 0,
+        diaryName = "",
+        classId = 0,
+        isCurrent = current,
+        semesterName = 0,
+        unitId = 0
+    )
+}
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/StudentRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/student/StudentRemoteTest.kt
similarity index 87%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/StudentRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/student/StudentRemoteTest.kt
index 3a26836de..1244239e8 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/StudentRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/student/StudentRemoteTest.kt
@@ -1,8 +1,7 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.student
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.register.Student
-import io.github.wulkanowy.data.repositories.student.StudentRemote
 import io.reactivex.Single
 import org.junit.Assert.assertEquals
 import org.junit.Before
diff --git a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/TimetableRemoteTest.kt b/app/src/test/java/io/github/wulkanowy/data/repositories/timetable/TimetableRemoteTest.kt
similarity index 96%
rename from app/src/test/java/io/github/wulkanowy/data/repositories/remote/TimetableRemoteTest.kt
rename to app/src/test/java/io/github/wulkanowy/data/repositories/timetable/TimetableRemoteTest.kt
index 942b28ed9..4bb4091fb 100644
--- a/app/src/test/java/io/github/wulkanowy/data/repositories/remote/TimetableRemoteTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/data/repositories/timetable/TimetableRemoteTest.kt
@@ -1,4 +1,4 @@
-package io.github.wulkanowy.data.repositories.remote
+package io.github.wulkanowy.data.repositories.timetable
 
 import io.github.wulkanowy.api.Api
 import io.github.wulkanowy.api.timetable.Timetable