diff --git a/.travis.yml b/.travis.yml
index d858cf3e..4bb84282 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@ cache:
 branches:
   only:
     - develop
-    - 0.18.1
+    - 0.18.2
 
 android:
  licenses:
diff --git a/app/build.gradle b/app/build.gradle
index 31cada74..e2aab017 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -17,8 +17,8 @@ android {
         testApplicationId "io.github.tests.wulkanowy"
         minSdkVersion 17
         targetSdkVersion 29
-        versionCode 60
-        versionName "0.18.1"
+        versionCode 61
+        versionName "0.18.2"
         multiDexEnabled true
         resValue "string", "app_name", "Wulkanowy"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -114,7 +114,7 @@ play {
 ext {
     work_manager = "2.3.4"
     room = "2.2.5"
-    dagger = "2.27"
+    dagger = "2.28"
     chucker = "3.2.0"
     mockk = "1.9.2"
 }
@@ -124,7 +124,7 @@ configurations.all {
 }
 
 dependencies {
-    implementation "io.github.wulkanowy:sdk:0.18.1"
+    implementation "io.github.wulkanowy:sdk:0.18.2"
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
     implementation "androidx.core:core-ktx:1.2.0"
diff --git a/app/src/main/java/io/github/wulkanowy/services/alarm/TimetableNotificationSchedulerHelper.kt b/app/src/main/java/io/github/wulkanowy/services/alarm/TimetableNotificationSchedulerHelper.kt
index 5374c476..54b245dd 100644
--- a/app/src/main/java/io/github/wulkanowy/services/alarm/TimetableNotificationSchedulerHelper.kt
+++ b/app/src/main/java/io/github/wulkanowy/services/alarm/TimetableNotificationSchedulerHelper.kt
@@ -3,7 +3,7 @@ package io.github.wulkanowy.services.alarm
 import android.app.AlarmManager
 import android.app.AlarmManager.RTC_WAKEUP
 import android.app.PendingIntent
-import android.app.PendingIntent.FLAG_CANCEL_CURRENT
+import android.app.PendingIntent.FLAG_UPDATE_CURRENT
 import android.content.Context
 import android.content.Intent
 import androidx.core.app.AlarmManagerCompat
@@ -55,7 +55,7 @@ class TimetableNotificationSchedulerHelper @Inject constructor(
 
     private fun cancelScheduledTo(range: ClosedRange<LocalDateTime>, requestCode: Int) {
         if (now() in range) cancelNotification()
-        alarmManager.cancel(PendingIntent.getBroadcast(context, requestCode, Intent(), FLAG_CANCEL_CURRENT))
+        alarmManager.cancel(PendingIntent.getBroadcast(context, requestCode, Intent(), FLAG_UPDATE_CURRENT))
     }
 
     fun cancelNotification() = NotificationManagerCompat.from(context).cancel(MainView.Section.TIMETABLE.id)
@@ -102,7 +102,7 @@ class TimetableNotificationSchedulerHelper @Inject constructor(
             PendingIntent.getBroadcast(context, getRequestCode(time, studentId), intent.also {
                 it.putExtra(NOTIFICATION_ID, MainView.Section.TIMETABLE.id)
                 it.putExtra(LESSON_TYPE, notificationType)
-            }, FLAG_CANCEL_CURRENT)
+            }, FLAG_UPDATE_CURRENT)
         )
         Timber.d("TimetableNotification scheduled: type: $notificationType, subject: ${intent.getStringExtra(LESSON_TITLE)}, start: $time, student: $studentId")
     }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProvider.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProvider.kt
index 954b5756..9582a5db 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProvider.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProvider.kt
@@ -1,5 +1,7 @@
 package io.github.wulkanowy.ui.modules.grade
 
+import io.github.wulkanowy.data.db.entities.Grade
+import io.github.wulkanowy.data.db.entities.GradeSummary
 import io.github.wulkanowy.data.db.entities.Semester
 import io.github.wulkanowy.data.db.entities.Student
 import io.github.wulkanowy.data.repositories.grade.GradeRepository
@@ -58,15 +60,14 @@ class GradeAverageProvider @Inject constructor(
             val isAnyAverage = summaries.any { it.average != .0 }
             val allGrades = details.groupBy { it.subject }
 
-            summaries.map { summary ->
+            summaries.emulateEmptySummaries(student, semester, allGrades.toList(), isAnyAverage).map { summary ->
                 val grades = allGrades[summary.subject].orEmpty()
                 GradeDetailsWithAverage(
                     subject = summary.subject,
                     average = if (!isAnyAverage || preferencesRepository.gradeAverageForceCalc) {
-                        grades.map {
-                            if (student.loginMode == Sdk.Mode.SCRAPPER.name) it.changeModifier(plusModifier, minusModifier)
-                            else it
-                        }.calcAverage()
+                        (if (student.loginMode == Sdk.Mode.SCRAPPER.name)
+                            grades.map { it.changeModifier(plusModifier, minusModifier) }
+                        else grades).calcAverage()
                     } else summary.average,
                     points = summary.pointsSum,
                     summary = summary,
@@ -75,4 +76,26 @@ class GradeAverageProvider @Inject constructor(
             }
         }
     }
+
+    private fun List<GradeSummary>.emulateEmptySummaries(student: Student, semester: Semester, grades: List<Pair<String, List<Grade>>>, calcAverage: Boolean): List<GradeSummary> {
+        if (isNotEmpty() && size == grades.size) return this
+
+        return grades.mapIndexed { i, (subject, details) ->
+            singleOrNull { it.subject == subject }?.let { return@mapIndexed it }
+            GradeSummary(
+                studentId = student.studentId,
+                semesterId = semester.semesterId,
+                position = i,
+                subject = subject,
+                predictedGrade = "",
+                finalGrade = "",
+                proposedPoints = "",
+                finalPoints = "",
+                pointsSum = "",
+                average = if (calcAverage) (if (student.loginMode == Sdk.Mode.SCRAPPER.name) {
+                    details.map { it.changeModifier(plusModifier, minusModifier) }
+                } else details).calcAverage() else .0
+            )
+        }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsAdapter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsAdapter.kt
index d5e05f3b..c129d948 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsAdapter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/details/GradeDetailsAdapter.kt
@@ -7,6 +7,7 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.NO_POSITION
 import io.github.wulkanowy.R
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.databinding.HeaderGradeDetailsBinding
@@ -23,7 +24,7 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
 
     private var items = mutableListOf<GradeDetailsItem>()
 
-    private var expandedPosition = RecyclerView.NO_POSITION
+    private var expandedPosition = NO_POSITION
 
     private var isExpandable = false
 
@@ -35,7 +36,7 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
         headers = data.filter { it.viewType == ViewType.HEADER }.toMutableList()
         items = if (isExpanded) headers else data.toMutableList()
         isExpandable = isExpanded
-        expandedPosition = RecyclerView.NO_POSITION
+        expandedPosition = NO_POSITION
     }
 
     fun updateDetailsItem(position: Int, grade: Grade) {
@@ -48,37 +49,40 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
     }
 
     fun getHeaderItem(subject: String): GradeDetailsItem {
-        if (headers.any { it.value !is GradeDetailsHeader }) {
-            Timber.e("Headers contains no-header items! $headers")
-        }
-
         val candidates = headers.filter { (it.value as GradeDetailsHeader).subject == subject }
 
         if (candidates.size > 1) {
-            Timber.e("Header with subject $subject found ${candidates.size} times! Items: $candidates, expanded: $expandedPosition")
+            Timber.e("Header with subject $subject found ${candidates.size} times! Expanded: $expandedPosition. Items: $candidates")
         }
 
         return candidates.first()
     }
 
     fun updateHeaderItem(item: GradeDetailsItem) {
-        headers[headers.indexOf(item)] = item
-        items[items.indexOf(item)] = item
-        notifyItemChanged(items.indexOf(item))
+        val headerPosition = headers.indexOf(item)
+        val itemPosition = items.indexOf(item)
+
+        if (headerPosition == NO_POSITION || itemPosition == NO_POSITION) {
+            Timber.e("Invalid update header positions! Header: $headerPosition, item: $itemPosition")
+        }
+
+        headers[headerPosition] = item
+        items[itemPosition] = item
+        notifyItemChanged(itemPosition)
     }
 
     fun collapseAll() {
         if (expandedPosition != -1) {
             refreshList(headers)
-            expandedPosition = RecyclerView.NO_POSITION
+            expandedPosition = NO_POSITION
         }
     }
 
     @Synchronized
-    private fun refreshList(newItems: List<GradeDetailsItem>) {
+    private fun refreshList(newItems: MutableList<GradeDetailsItem>) {
         val diffCallback = GradeDetailsDiffUtil(items, newItems)
         val diffResult = DiffUtil.calculateDiff(diffCallback)
-        items = newItems.toMutableList()
+        items = newItems
         diffResult.dispatchUpdatesTo(this)
     }
 
@@ -99,23 +103,24 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
         when (holder) {
             is HeaderViewHolder -> bindHeaderViewHolder(
-                binding = holder.binding,
+                holder = holder,
                 header = items[position].value as GradeDetailsHeader,
-                headerPosition = headers.indexOf(items[position]),
-                adapterPosition = position
+                position = position
             )
             is ItemViewHolder -> bindItemViewHolder(
-                binding = holder.binding,
-                grade = items[position].value as Grade,
-                position = holder.adapterPosition
+                holder = holder,
+                grade = items[position].value as Grade
             )
         }
     }
 
-    private fun bindHeaderViewHolder(binding: HeaderGradeDetailsBinding, header: GradeDetailsHeader, headerPosition: Int, adapterPosition: Int) {
-        with(binding) {
+    private fun bindHeaderViewHolder(holder: HeaderViewHolder, header: GradeDetailsHeader, position: Int) {
+        val headerPosition = headers.indexOf(items[position])
+        val adapterPosition = holder.adapterPosition
+
+        with(holder.binding) {
             gradeHeaderDivider.visibility = if (adapterPosition == 0) View.GONE else View.VISIBLE
-            gradeHeaderSubject.apply {
+            with(gradeHeaderSubject) {
                 text = header.subject
                 maxLines = if (headerPosition == expandedPosition) 2 else 1
             }
@@ -130,7 +135,7 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
             gradeHeaderContainer.setOnClickListener {
                 expandedPosition = if (expandedPosition == adapterPosition) -1 else adapterPosition
 
-                if (expandedPosition != RecyclerView.NO_POSITION) {
+                if (expandedPosition != NO_POSITION) {
                     refreshList(headers.toMutableList().apply {
                         addAll(headerPosition + 1, header.grades)
                     })
@@ -148,8 +153,8 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
     }
 
     @SuppressLint("SetTextI18n")
-    private fun bindItemViewHolder(binding: ItemGradeDetailsBinding, grade: Grade, position: Int) {
-        with(binding) {
+    private fun bindItemViewHolder(holder: ItemViewHolder, grade: Grade) {
+        with(holder.binding) {
             gradeItemValue.run {
                 text = grade.entry
                 setBackgroundResource(grade.getBackgroundColor(colorTheme))
@@ -163,7 +168,9 @@ class GradeDetailsAdapter @Inject constructor() : BaseExpandableAdapter<Recycler
             gradeItemWeight.text = "${root.context.getString(R.string.grade_weight)}: ${grade.weight}"
             gradeItemNote.visibility = if (!grade.isRead) View.VISIBLE else View.GONE
 
-            root.setOnClickListener { onClickListener(grade, position) }
+            root.setOnClickListener {
+                holder.adapterPosition.let { if (it != NO_POSITION) onClickListener(grade, it) }
+            }
         }
     }
 
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryPresenter.kt
index 9b88689d..229a0107 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/summary/GradeSummaryPresenter.kt
@@ -109,7 +109,17 @@ class GradeSummaryPresenter @Inject constructor(
 
     private fun createGradeSummaryItems(items: List<GradeDetailsWithAverage>): List<GradeSummary> {
         return items
+            .filter { !checkEmpty(it) }
             .sortedBy { it.subject }
             .map { it.summary.copy(average = it.average) }
     }
+
+    private fun checkEmpty(gradeSummary: GradeDetailsWithAverage): Boolean {
+        return gradeSummary.run {
+            summary.finalGrade.isBlank()
+                && summary.predictedGrade.isBlank()
+                && average == .0
+                && points.isBlank()
+        }
+    }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectAdapter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectAdapter.kt
index 7383a5ec..3332f2be 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectAdapter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectAdapter.kt
@@ -12,7 +12,13 @@ import javax.inject.Inject
 class LoginStudentSelectAdapter @Inject constructor() :
     RecyclerView.Adapter<LoginStudentSelectAdapter.ItemViewHolder>() {
 
+    private val checkedList = mutableMapOf<Int, Boolean>()
+
     var items = emptyList<Pair<Student, Boolean>>()
+        set(value) {
+            field = value
+            checkedList.clear()
+        }
 
     var onClickListener: (Student, alreadySaved: Boolean) -> Unit = { _, _ -> }
 
@@ -31,15 +37,21 @@ class LoginStudentSelectAdapter @Inject constructor() :
             loginItemSchool.text = student.schoolName
             loginItemName.isEnabled = !alreadySaved
             loginItemSchool.isEnabled = !alreadySaved
-            loginItemCheck.isEnabled = !alreadySaved
             loginItemSignedIn.visibility = if (alreadySaved) View.VISIBLE else View.GONE
 
+            with(loginItemCheck) {
+                isEnabled = !alreadySaved
+                keyListener = null
+                isChecked = checkedList[position] ?: false
+            }
+
             root.setOnClickListener {
                 onClickListener(student, alreadySaved)
 
                 with(loginItemCheck) {
                     if (isEnabled) {
                         isChecked = !isChecked
+                        checkedList[position] = isChecked
                     }
                 }
             }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectPresenter.kt
index b2d0aed9..db25c0da 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/login/studentselect/LoginStudentSelectPresenter.kt
@@ -22,7 +22,7 @@ class LoginStudentSelectPresenter @Inject constructor(
 
     var students = emptyList<Student>()
 
-    private var selectedStudents = mutableListOf<Student>()
+    private val selectedStudents = mutableListOf<Student>()
 
     fun onAttachView(view: LoginStudentSelectView, students: Serializable?) {
         super.onAttachView(view)
@@ -69,6 +69,7 @@ class LoginStudentSelectPresenter @Inject constructor(
     }
 
     private fun loadData(students: List<Student>) {
+        resetSelectedState()
         this.students = students
         disposable.add(studentRepository.getSavedStudents()
             .map { savedStudents ->
@@ -88,6 +89,11 @@ class LoginStudentSelectPresenter @Inject constructor(
         )
     }
 
+    private fun resetSelectedState() {
+        selectedStudents.clear()
+        view?.enableSignIn(false)
+    }
+
     private fun registerStudents(students: List<Student>) {
         disposable.add(studentRepository.saveStudents(students)
             .map { students.first().apply { id = it.first() } }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabAdapter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabAdapter.kt
index 6064f10a..ece6773f 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabAdapter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabAdapter.kt
@@ -5,6 +5,7 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.NO_POSITION
 import androidx.recyclerview.widget.SortedList
 import androidx.recyclerview.widget.SortedListAdapterCallback
 import io.github.wulkanowy.R
@@ -77,7 +78,9 @@ class MessageTabAdapter @Inject constructor() :
             }
             messageItemAttachmentIcon.visibility = if (item.hasAttachments) View.VISIBLE else View.GONE
 
-            root.setOnClickListener { onClickListener(item, holder.adapterPosition) }
+            root.setOnClickListener {
+                holder.adapterPosition.let { if (it != NO_POSITION) onClickListener(item, it) }
+            }
         }
     }
 
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 7243061d..92aeb581 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
@@ -43,6 +43,7 @@ class CompletedLessonsPresenter @Inject constructor(
         completedLessonsErrorHandler.showErrorMessage = ::showErrorViewOnError
         completedLessonsErrorHandler.onFeatureDisabled = {
             this.view?.showFeatureDisabled()
+            this.view?.showEmpty(true);
             Timber.i("Completed lessons feature disabled by school")
         }
         loadData(ofEpochDay(date ?: baseDate.toEpochDay()))
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 d61f1b97..1908d2e2 100644
--- a/app/src/main/play/release-notes/pl-PL/default.txt
+++ b/app/src/main/play/release-notes/pl-PL/default.txt
@@ -1,8 +1,9 @@
-Wersja 0.18.1
-- naprawiliśmy sortowanie w ocenach
-- naprawilismy wiele problemów ze stabilnością
-- nazwy opcji w ustawieniach nie są już ucięte
-- w zadaniach domowych wyświetlają się teraz pozycje na weekend
-- wyłączyliśmy logowanie przez token (bo nie działa i nie wiadomo kiedy będzie działać)
+Wersja 0.18.2
+- naprawiliśmy zaznaczanie uczniów przy logowaniu
+- naprawiliśmy odświeżanie planu lekcji na samsungach
+- naprawiliśmy wysyłanie wiadomości
+- poprawiliśmy oznaczanie nowych wiadomości jako przeczytanych
+- w podsumowaniu ocen nie będą się już pokazywać „puste” przedmioty
+- w polu pisania wiadomości pierwsza litera w zdaniu będzie teraz domyślnie duża
 
 Pełna lista zmian: https://github.com/wulkanowy/wulkanowy/releases
diff --git a/app/src/main/res/layout/activity_send_message.xml b/app/src/main/res/layout/activity_send_message.xml
index f59dcabd..e0ec52bb 100644
--- a/app/src/main/res/layout/activity_send_message.xml
+++ b/app/src/main/res/layout/activity_send_message.xml
@@ -148,7 +148,7 @@
                     android:hint="@string/message_content"
                     android:imeOptions="flagNoExtractUi"
                     android:importantForAutofill="no"
-                    android:inputType="textMultiLine"
+                    android:inputType="textMultiLine|textCapSentences"
                     android:minHeight="58dp"
                     android:paddingStart="16dp"
                     android:paddingLeft="16dp"
diff --git a/app/src/main/res/layout/fragment_login_student_select.xml b/app/src/main/res/layout/fragment_login_student_select.xml
index 64e06cbd..f9c6c157 100644
--- a/app/src/main/res/layout/fragment_login_student_select.xml
+++ b/app/src/main/res/layout/fragment_login_student_select.xml
@@ -24,10 +24,10 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="vertical"
+            android:visibility="gone"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent"
-            android:visibility="gone"
             tools:visibility="visible">
 
             <View
@@ -42,9 +42,9 @@
                 android:layout_height="wrap_content"
                 android:layout_marginStart="32dp"
                 android:layout_marginLeft="32dp"
+                android:layout_marginTop="16dp"
                 android:layout_marginEnd="32dp"
                 android:layout_marginRight="32dp"
-                android:layout_marginTop="16dp"
                 android:layout_marginBottom="16dp"
                 android:gravity="center_horizontal"
                 android:text="@string/login_contact_header"
@@ -55,28 +55,29 @@
                 android:id="@+id/loginStudentSelectContactButtons"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:orientation="horizontal"
                 android:layout_marginLeft="16dp"
-                android:layout_marginRight="16dp">
+                android:layout_marginRight="16dp"
+                android:orientation="horizontal">
+
                 <com.google.android.material.button.MaterialButton
-                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
                     android:id="@+id/loginStudentSelectContactEmail"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:layout_marginRight="8dp"
                     android:layout_marginEnd="8dp"
+                    android:layout_marginRight="8dp"
+                    android:layout_weight="1"
                     android:text="@string/login_contact_email"
                     app:icon="@drawable/ic_more_messages" />
 
                 <com.google.android.material.button.MaterialButton
-                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
                     android:id="@+id/loginStudentSelectContactDiscord"
+                    style="@style/Widget.MaterialComponents.Button.OutlinedButton"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:layout_marginLeft="8dp"
                     android:layout_marginStart="8dp"
+                    android:layout_marginLeft="8dp"
+                    android:layout_weight="1"
                     android:text="@string/login_contact_discord"
                     app:icon="@drawable/ic_about_discord" />
             </LinearLayout>
@@ -95,9 +96,9 @@
             android:layout_height="wrap_content"
             android:layout_marginStart="32dp"
             android:layout_marginLeft="32dp"
+            android:layout_marginTop="32dp"
             android:layout_marginEnd="32dp"
             android:layout_marginRight="32dp"
-            android:layout_marginTop="32dp"
             android:layout_marginBottom="32dp"
             android:gravity="center_horizontal"
             android:text="@string/login_select_student"
@@ -129,8 +130,8 @@
             android:layout_height="wrap_content"
             android:layout_marginTop="32dp"
             android:layout_marginEnd="24dp"
-            android:layout_marginRight="24dp"
             android:layout_marginBottom="32dp"
+            android:enabled="false"
             android:text="@string/login_sign_in"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
diff --git a/app/src/main/res/values-ru/strings.xml b/app/src/main/res/values-ru/strings.xml
index c0c75196..6eb8f774 100644
--- a/app/src/main/res/values-ru/strings.xml
+++ b/app/src/main/res/values-ru/strings.xml
@@ -290,8 +290,8 @@
     <string name="logviewer_share">Поделиться логами</string>
     <string name="logviewer_refresh">Обновить</string>
     <!--Error dialog-->
-    <string name="dialog_error_check_update">Check for updates</string>
-    <string name="dialog_error_check_update_message">Before reporting a bug, check first if an update with the bug fix is available</string>
+    <string name="dialog_error_check_update">Проверить наличие обновлений</string>
+    <string name="dialog_error_check_update_message">Прежде чем сообщать об ошибке, проверьте наличие обновлений</string>
     <!--Generic-->
     <string name="all_content">Содержание</string>
     <string name="all_retry">Повторить</string>
diff --git a/app/src/main/res/values-uk/strings.xml b/app/src/main/res/values-uk/strings.xml
index a63e5682..ec4dbc15 100644
--- a/app/src/main/res/values-uk/strings.xml
+++ b/app/src/main/res/values-uk/strings.xml
@@ -120,14 +120,14 @@
     <string name="timetable_time">Години</string>
     <string name="timetable_changes">Зміни</string>
     <string name="timetable_no_items">Брак уроків у цей день</string>
-    <string name="timetable_minutes">%s min</string>
-    <string name="timetable_seconds">%s sec</string>
-    <string name="timetable_time_left">%1$s left</string>
-    <string name="timetable_time_until">in %1$s</string>
-    <string name="timetable_finished">Finished</string>
-    <string name="timetable_now">Now: %s</string>
-    <string name="timetable_next">Next: %s</string>
-    <string name="timetable_later">Later: %s</string>
+    <string name="timetable_minutes">%s хвилин</string>
+    <string name="timetable_seconds">%s сек</string>
+    <string name="timetable_time_left">%1$s лишилося</string>
+    <string name="timetable_time_until">через %1$s</string>
+    <string name="timetable_finished">Завершено</string>
+    <string name="timetable_now">Зараз: %s</string>
+    <string name="timetable_next">Наступний: %s</string>
+    <string name="timetable_later">Пізніше: %s</string>
     <!--Completed lessons-->
     <string name="completed_lessons_title">Уроки, що відбулися</string>
     <string name="completed_lessons_button">Показати уроки, що відбулися</string>
@@ -290,8 +290,8 @@
     <string name="logviewer_share">Поділитися логами</string>
     <string name="logviewer_refresh">Оновити</string>
     <!--Error dialog-->
-    <string name="dialog_error_check_update">Check for updates</string>
-    <string name="dialog_error_check_update_message">Before reporting a bug, check first if an update with the bug fix is available</string>
+    <string name="dialog_error_check_update">Провірити наявність оновлень</string>
+    <string name="dialog_error_check_update_message">Перед тим, як повідомлювати о помілці, перевірте наявність оновлень</string>
     <!--Generic-->
     <string name="all_content">Зміст</string>
     <string name="all_retry">Повторити</string>
@@ -308,8 +308,8 @@
     <string name="all_subject">Предмет</string>
     <string name="all_prev">Попередній</string>
     <string name="all_next">Наступний</string>
-    <string name="all_search">Search</string>
-    <string name="all_search_hint">Search...</string>
+    <string name="all_search">Пошук</string>
+    <string name="all_search_hint">Пошук...</string>
     <!--Timetable Widget-->
     <string name="widget_timetable_no_items">Брак уроків</string>
     <string name="widget_timetable_theme_title">Увібрати тему</string>
@@ -324,17 +324,17 @@
     <string name="pref_view_present">Показувати присутність у відвідуваності</string>
     <string name="pref_view_app_theme">Тема додатку</string>
     <string name="pref_view_expand_grade">Більше оцінок</string>
-    <string name="pref_view_timetable_show_timers">Mark current lesson in timetable</string>
-    <string name="pref_view_grade_statistics_list">Show chart list in class grades</string>
+    <string name="pref_view_timetable_show_timers">Позначити поточний урок у розкладі</string>
+    <string name="pref_view_grade_statistics_list">Показувати діаграми в оцінках класу</string>
     <string name="pref_view_timetable_show_whole_class">Показати уроки всього класу</string>
     <string name="pref_view_grade_color_scheme">Схема кольорів оцінок</string>
     <string name="pref_view_app_language">Мова додатку</string>
     <string name="pref_notify_header">Повідомлення</string>
     <string name="pref_notify_switch">Показувати повідомлення</string>
-    <string name="pref_notify_upcoming_lessons_switch">Show upcoming lesson notifications</string>
-    <string name="pref_notify_fix_sync_issues">Fix synchronization &amp; notifications issues</string>
-    <string name="pref_notify_fix_sync_issues_message">Your device may have data synchronization issues and with notifications.\n\nTo fix them, you need to add Wulkanowy to the autostart and turn off battery optimization/saving in the phone settings.</string>
-    <string name="pref_notify_fix_sync_issues_settings_button">Go to settings</string>
+    <string name="pref_notify_upcoming_lessons_switch">Показувати повідомлення о наступних уроках</string>
+    <string name="pref_notify_fix_sync_issues">Виправити помилки з синхронізацією і повідомленнями</string>
+    <string name="pref_notify_fix_sync_issues_message">На вашому пристрої можуть бути помилки з синхронізацією і повідомленнями\n\nЩоб виправити іх, вам необхідно додати Wulkanowy в авто-старт и вимкнути оптимізацію/экономію батареї в налаштуваннях пристрою.</string>
+    <string name="pref_notify_fix_sync_issues_settings_button">Перейти до налаштувань</string>
     <string name="pref_notify_debug_switch">Показувати дебаг-повідомлення</string>
     <string name="pref_services_header">Синхронізація</string>
     <string name="pref_services_switch">Автоматична синхронізація</string>
@@ -360,7 +360,7 @@
     <string name="channel_new_message">Нові повідомлення</string>
     <string name="channel_new_notes">Нові нотатки</string>
     <string name="channel_push">Показувати push-повідомлення</string>
-    <string name="channel_upcoming_lessons">Upcoming lessons</string>
+    <string name="channel_upcoming_lessons">Наступні уроки</string>
     <string name="channel_debug">Дебаг</string>
     <!--Colors-->
     <string name="all_black">Чорний</string>
diff --git a/app/src/test/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProviderTest.kt b/app/src/test/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProviderTest.kt
index fcc30593..ee8634ca 100644
--- a/app/src/test/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProviderTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/ui/modules/grade/GradeAverageProviderTest.kt
@@ -1,11 +1,11 @@
 package io.github.wulkanowy.ui.modules.grade
 
+import io.github.wulkanowy.createSemesterEntity
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.data.db.entities.GradeSummary
 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.createSemesterEntity
 import io.github.wulkanowy.data.repositories.semester.SemesterRepository
 import io.github.wulkanowy.sdk.Sdk
 import io.reactivex.Single
@@ -84,8 +84,6 @@ class GradeAverageProviderTest {
     fun setUp() {
         MockitoAnnotations.initMocks(this)
 
-        `when`(preferencesRepository.gradeMinusModifier).thenReturn(.33)
-        `when`(preferencesRepository.gradePlusModifier).thenReturn(.33)
         `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
         `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
 
@@ -93,7 +91,83 @@ class GradeAverageProviderTest {
     }
 
     @Test
-    fun onlyOneSemesterTest() {
+    fun `force calc current semester average with default modifiers in scraper mode`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
+        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(3.5, items.single { it.subject == "Język polski" }.average, .0) // from details and after set custom plus/minus
+    }
+
+    @Test
+    fun `force calc current semester average with custom modifiers in scraper mode`() {
+        val student = student.copy(loginMode = Sdk.Mode.SCRAPPER.name)
+
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeMinusModifier).thenReturn(.33)
+        `when`(preferencesRepository.gradePlusModifier).thenReturn(.33)
+
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
+        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(3.5, items.single { it.subject == "Język polski" }.average, .0) // from details and after set custom plus/minus
+    }
+
+    @Test
+    fun `force calc current semester average with custom modifiers in api mode`() {
+        val student = student.copy(loginMode = Sdk.Mode.API.name)
+
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeMinusModifier).thenReturn(.33) // useless in this mode
+        `when`(preferencesRepository.gradePlusModifier).thenReturn(.33)
+
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
+        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(3.375, items.single { it.subject == "Język polski" }.average, .0) // (from details): 3.375
+    }
+
+    @Test
+    fun `force calc current semester average with custom modifiers in hybrid mode`() {
+        val student = student.copy(loginMode = Sdk.Mode.HYBRID.name)
+
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeMinusModifier).thenReturn(.33) // useless in this mode
+        `when`(preferencesRepository.gradePlusModifier).thenReturn(.33)
+
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
+        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(3.375, items.single { it.subject == "Język polski" }.average, .0) // (from details): 3.375
+    }
+
+    @Test
+    fun `calc current semester average`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(2.9, items.single { it.subject == "Matematyka" }.average, .0) // from summary: 2,9
+        assertEquals(3.4, items.single { it.subject == "Fizyka" }.average, .0) // from details: 3,4
+    }
+
+    @Test
+    fun `force calc current semester average`() {
         `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
         `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
         `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries))
@@ -101,65 +175,12 @@ class GradeAverageProviderTest {
         val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
 
         assertEquals(2, items.size)
-        assertEquals(2.5, items.single { it.subject == "Matematyka" }.average, .0)
-        assertEquals(3.0, items.single { it.subject == "Fizyka" }.average, .0)
+        assertEquals(2.5, items.single { it.subject == "Matematyka" }.average, .0) // from details: 2,5
+        assertEquals(3.0, items.single { it.subject == "Fizyka" }.average, .0) // from details: 3,0
     }
 
     @Test
-    fun onlyOneSemester_gradesWithModifiers_default() {
-        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
-        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
-
-        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
-
-        assertEquals(3.5, items.single { it.subject == "Język polski" }.average, .0)
-    }
-
-    @Test
-    fun onlyOneSemester_gradesWithModifiers_api() {
-        val student = student.copy(loginMode = Sdk.Mode.API.name)
-
-        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
-        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
-        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
-
-        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
-
-        assertEquals(3.375, items.single { it.subject == "Język polski" }.average, .0)
-    }
-
-    @Test
-    fun onlyOneSemester_gradesWithModifiers_scrapper() {
-        val student = student.copy(loginMode = Sdk.Mode.SCRAPPER.name)
-
-        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
-        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
-        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
-
-        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
-
-        assertEquals(3.5, items.single { it.subject == "Język polski" }.average, .0)
-    }
-
-    @Test
-    fun onlyOneSemester_gradesWithModifiers_hybrid() {
-        val student = student.copy(loginMode = Sdk.Mode.HYBRID.name)
-
-        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("only_one_semester")
-        `when`(semesterRepository.getSemesters(student)).thenReturn(Single.just(semesters))
-        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGradeWithModifier to secondSummariesWithModifier))
-
-        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
-
-        assertEquals(3.375, items.single { it.subject == "Język polski" }.average, .0)
-    }
-
-    @Test
-    fun allYearFirstSemesterTest() {
+    fun `force calc full year average when current is first`() {
         `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
         `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
         `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries))
@@ -167,33 +188,19 @@ class GradeAverageProviderTest {
         val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[1].semesterId).blockingGet()
 
         assertEquals(2, items.size)
-        assertEquals(3.5, items.single { it.subject == "Matematyka" }.average, .0)
-        assertEquals(3.5, items.single { it.subject == "Fizyka" }.average, .0)
-    }
-
-    @Test
-    fun allYearSecondSemesterTest() {
-        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
-        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries))
-        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries))
-
-        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
-
-        assertEquals(2, items.size)
-        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0)
-        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0)
+        assertEquals(3.5, items.single { it.subject == "Matematyka" }.average, .0) // (from summary): 3,5
+        assertEquals(3.5, items.single { it.subject == "Fizyka" }.average, .0) // (from summary): 3,5
     }
 
     @Test(expected = IllegalArgumentException::class)
-    fun incorrectAverageModeTest() {
+    fun `calc average on invalid mode`() {
         `when`(preferencesRepository.gradeAverageMode).thenReturn("test_mode")
 
         gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId, true).blockingGet()
     }
 
     @Test
-    fun allYearSemester_averageFromSummary() {
+    fun `calc full year average`() {
         `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
         `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
         `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to listOf(
@@ -208,14 +215,14 @@ class GradeAverageProviderTest {
         val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
 
         assertEquals(2, items.size)
-        assertEquals(3.25, items.single { it.subject == "Matematyka" }.average, .0)
-        assertEquals(3.75, items.single { it.subject == "Fizyka" }.average, .0)
+        assertEquals(3.25, items.single { it.subject == "Matematyka" }.average, .0) // (from summaries ↑): 3,0 + 3,5 → 3,25
+        assertEquals(3.75, items.single { it.subject == "Fizyka" }.average, .0) // (from summaries ↑): 3,5 + 4,0 → 3,75
     }
 
     @Test
-    fun onlyOneSemester_averageFromSummary_forceCalc() {
-        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+    fun `force calc full year average`() {
         `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
         `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries))
         `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to listOf(
             getSummary(22, "Matematyka", 1.1),
@@ -225,8 +232,102 @@ class GradeAverageProviderTest {
         val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
 
         assertEquals(2, items.size)
-        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0)
-        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0)
+        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0) // (from details): 3,5 + 2,5 → 3,0
+        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0) // (from details): 3,5  + 3,0 → 3,25
+    }
+
+    @Test
+    fun `calc full year average when no summaries`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to emptyList()))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to emptyList()))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0) // (from details): 2,5 + 3,5 → 3,0
+        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0) // (from details): 3,5  + 3,0 → 3,25
+    }
+
+    @Test
+    fun `force calc full year average when no summaries`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to emptyList()))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to emptyList()))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0) // (from details): 3,5 + 2,5 → 3,0
+        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0) // (from details): 3,5  + 3,0 → 3,25
+    }
+
+    @Test
+    fun `calc full year average when missing summaries in both semesters`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to listOf(
+            getSummary(22, "Matematyka", 4.0)
+        )))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to listOf(
+            getSummary(23, "Matematyka", 3.0)
+        )))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.5, items.single { it.subject == "Matematyka" }.average, .0) // (from summaries ↑): 4,0 + 3,0 → 3,5
+        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0) // (from details): 3,5  + 3,0 → 3,25
+    }
+
+    @Test
+    fun `calc full year average when missing summary in second semester`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries.dropLast(1)))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.4, items.single { it.subject == "Matematyka" }.average, .0) // (from summaries): 3,9 + 2,9 → 3,4
+        assertEquals(3.05, items.single { it.subject == "Fizyka" }.average, .0) // 3,1 (from summary) + 3,0 (from details) → 3,05
+    }
+
+    @Test
+    fun `calc full year average when missing summary in first semester`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(false)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries.dropLast(1)))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.4, items.single { it.subject == "Matematyka" }.average, .0) // (from summaries): 3,9 + 2,9 → 3,4
+        assertEquals(3.45, items.single { it.subject == "Fizyka" }.average, .0) // 3,5 (from details) + 3,4 (from summary) → 3,45
+    }
+
+    @Test
+    fun `force calc full year average when missing summary in first semester`() {
+        `when`(preferencesRepository.gradeAverageForceCalc).thenReturn(true)
+        `when`(preferencesRepository.gradeAverageMode).thenReturn("all_year")
+
+        `when`(gradeRepository.getGrades(student, semesters[1])).thenReturn(Single.just(firstGrades to firstSummaries.dropLast(1)))
+        `when`(gradeRepository.getGrades(student, semesters[2])).thenReturn(Single.just(secondGrades to secondSummaries))
+
+        val items = gradeAverageProvider.getGradesDetailsWithAverage(student, semesters[2].semesterId).blockingGet()
+
+        assertEquals(2, items.size)
+        assertEquals(3.0, items.single { it.subject == "Matematyka" }.average, .0) // (from details): 3,5 + 2,5 → 3,0
+        assertEquals(3.25, items.single { it.subject == "Fizyka" }.average, .0) // (from details): 3,5  + 3,0 → 3,25
     }
 
     private fun getGrade(semesterId: Int, subject: String, value: Double, modifier: Double = 0.0): Grade {
diff --git a/build.gradle b/build.gradle
index 696e778f..7e5759d1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,6 @@
 buildscript {
     ext.kotlin_version = '1.3.72'
-    ext.about_libraries = '8.1.3'
+    ext.about_libraries = '8.1.6'
     repositories {
         mavenCentral()
         google()
@@ -9,7 +9,7 @@ buildscript {
     }
     dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-        classpath 'com.android.tools.build:gradle:3.6.3'
+        classpath 'com.android.tools.build:gradle:4.0.0'
         classpath 'com.google.gms:google-services:4.3.3'
         classpath 'com.google.firebase:firebase-crashlytics-gradle:2.1.1'
         classpath "com.github.triplet.gradle:play-publisher:2.7.5"