diff --git a/app/build.gradle b/app/build.gradle
index acf4ddd0..c20c80c5 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -177,11 +177,12 @@ dependencies {
     implementation "com.mikepenz:aboutlibraries-core:$about_libraries"
     implementation 'com.wdullaer:materialdatetimepicker:4.2.3'
     implementation "io.coil-kt:coil:0.11.0"
+    implementation "io.github.wulkanowy:AppKillerManager:c33b658"
 
     playImplementation 'com.google.firebase:firebase-analytics:17.4.1'
     playImplementation 'com.google.firebase:firebase-inappmessaging-display-ktx:19.0.6'
     playImplementation "com.google.firebase:firebase-inappmessaging-ktx:19.0.6"
-    playImplementation 'com.google.firebase:firebase-messaging:20.1.6'
+    playImplementation 'com.google.firebase:firebase-messaging:20.1.7'
     playImplementation 'com.google.firebase:firebase-crashlytics:17.0.0'
     playImplementation 'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava'
 
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 4ec2f781..802cf1ad 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -18,7 +18,8 @@
         android:supportsRtl="false"
         android:theme="@style/WulkanowyTheme"
         android:usesCleartextTraffic="true"
-        tools:ignore="GoogleAppIndexingWarning,UnusedAttribute">
+        tools:ignore="GoogleAppIndexingWarning,UnusedAttribute"
+        tools:replace="android:supportsRtl,android:allowBackup">
         <activity
             android:name=".ui.modules.splash.SplashActivity"
             android:screenOrientation="portrait"
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsFragment.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsFragment.kt
index aa38a87a..0d1d2565 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsFragment.kt
@@ -6,6 +6,7 @@ import android.os.Bundle
 import androidx.appcompat.app.AlertDialog
 import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
+import com.thelittlefireman.appkillermanager.AppKillerManager
 import com.yariksoffice.lingver.Lingver
 import dagger.android.support.AndroidSupportInjection
 import io.github.wulkanowy.R
@@ -50,6 +51,13 @@ class SettingsFragment : PreferenceFragmentCompat(),
                 true
             }
         }
+        findPreference<Preference>(getString(R.string.pref_key_notifications_fix_issues))?.run {
+            isVisible = AppKillerManager.isDeviceSupported() && AppKillerManager.isAnyActionAvailable(requireContext())
+            setOnPreferenceClickListener {
+                presenter.onFixSyncIssuesClicked()
+                true
+            }
+        }
     }
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {
@@ -119,6 +127,19 @@ class SettingsFragment : PreferenceFragmentCompat(),
             .show()
     }
 
+    override fun showFixSyncDialog() {
+        AlertDialog.Builder(requireContext())
+            .setTitle(R.string.pref_notify_fix_sync_issues)
+            .setMessage(R.string.pref_notify_fix_sync_issues_message)
+            .setNegativeButton(android.R.string.cancel) { _, _ -> }
+            .setPositiveButton(R.string.pref_notify_fix_sync_issues_settings_button) { _, _ ->
+                AppKillerManager.doActionPowerSaving(requireContext())
+                AppKillerManager.doActionAutoStart(requireContext())
+                AppKillerManager.doActionNotification(requireContext())
+            }
+            .show()
+    }
+
     override fun onResume() {
         super.onResume()
         preferenceScreen.sharedPreferences.registerOnSharedPreferenceChangeListener(this)
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
index 09fc2d70..bccb6f0b 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsPresenter.kt
@@ -58,6 +58,10 @@ class SettingsPresenter @Inject constructor(
         view?.showForceSyncDialog()
     }
 
+    fun onFixSyncIssuesClicked() {
+        view?.showFixSyncDialog()
+    }
+
     fun onForceSyncDialogSubmit() {
         view?.run {
             val successString = syncSuccessString
diff --git a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsView.kt b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsView.kt
index 4a1b0c76..3786ba4b 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/settings/SettingsView.kt
@@ -19,4 +19,5 @@ interface SettingsView : BaseView {
     fun setSyncInProgress(inProgress: Boolean)
 
     fun showForceSyncDialog()
+    fun showFixSyncDialog()
 }
diff --git a/app/src/main/res/values-pl/strings.xml b/app/src/main/res/values-pl/strings.xml
index a4af0dec..03ccaa2d 100644
--- a/app/src/main/res/values-pl/strings.xml
+++ b/app/src/main/res/values-pl/strings.xml
@@ -329,6 +329,9 @@
     <string name="pref_notify_header">Powiadomienia</string>
     <string name="pref_notify_switch">Pokazuj powiadomienia</string>
     <string name="pref_notify_upcoming_lessons_switch">Pokazuj powiadomienia o następnych lekcjach</string>
+    <string name="pref_notify_fix_sync_issues">Napraw problemy z synchronizacją i powiadomieniami</string>
+    <string name="pref_notify_fix_sync_issues_message">Na twoim urządzeniu mogą występować problemy z synchronizacją danych i powiadomieniami.\n\nBy je naprawić, dodaj Wulkanowego do autostartu i wyłącz optymalizację/oszczędzanie baterii w ustawieniach systemowych telefonu.</string>
+    <string name="pref_notify_fix_sync_issues_settings_button">Przejdź do ustawień</string>
     <string name="pref_notify_debug_switch">Pokazuj powiadomienia debugowania</string>
     <string name="pref_services_header">Synchronizacja</string>
     <string name="pref_services_switch">Automatyczna aktualizacja</string>
diff --git a/app/src/main/res/values/preferences_keys.xml b/app/src/main/res/values/preferences_keys.xml
index 868a3c89..6cb877ec 100644
--- a/app/src/main/res/values/preferences_keys.xml
+++ b/app/src/main/res/values/preferences_keys.xml
@@ -13,6 +13,7 @@
     <string name="pref_key_services_interval">services_interval</string>
     <string name="pref_key_services_wifi_only">services_disable_wifi_only</string>
     <string name="pref_key_services_force_sync">services_force_sync</string>
+    <string name="pref_key_notifications_fix_issues">notifications_fix_issues</string>
     <string name="pref_key_notifications_enable">notifications_enable</string>
     <string name="pref_key_notifications_upcoming_lessons_enable">notifications_upcoming_lessons_enable</string>
     <string name="pref_key_notification_debug">notification_debug</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 06f136c7..6e08fded 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -366,6 +366,9 @@
     <string name="pref_notify_header">Notifications</string>
     <string name="pref_notify_switch">Show notifications</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_debug_switch">Show debug notifications</string>
 
     <string name="pref_services_header">Synchronization</string>
diff --git a/app/src/main/res/xml/scheme_preferences.xml b/app/src/main/res/xml/scheme_preferences.xml
index a138177f..c05910f9 100644
--- a/app/src/main/res/xml/scheme_preferences.xml
+++ b/app/src/main/res/xml/scheme_preferences.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?><!--suppress AndroidElementNotAllowed -->
+<?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto">
     <PreferenceCategory
         app:iconSpaceReserved="false"
@@ -32,13 +32,13 @@
         <SwitchPreferenceCompat
             app:defaultValue="@bool/pref_default_timetable_show_timers"
             app:iconSpaceReserved="false"
-            app:title="@string/pref_view_timetable_show_timers"
-            app:key="@string/pref_key_timetable_show_timers" />
+            app:key="@string/pref_key_timetable_show_timers"
+            app:title="@string/pref_view_timetable_show_timers" />
         <SwitchPreferenceCompat
             app:defaultValue="@bool/pref_default_grade_statistics_list"
             app:iconSpaceReserved="false"
             app:key="@string/pref_key_grade_statistics_list"
-            app:title="@string/pref_view_grade_statistics_list"/>
+            app:title="@string/pref_view_grade_statistics_list" />
         <ListPreference
             app:defaultValue="@string/pref_default_timetable_show_whole_class"
             app:entries="@array/timetable_show_whole_class_entries"
@@ -95,6 +95,10 @@
     <PreferenceCategory
         app:iconSpaceReserved="false"
         app:title="@string/pref_notify_header">
+        <Preference
+            app:iconSpaceReserved="false"
+            app:key="@string/pref_key_notifications_fix_issues"
+            app:title="@string/pref_notify_fix_sync_issues" />
         <SwitchPreferenceCompat
             app:defaultValue="@bool/pref_default_notifications_enable"
             app:dependency="services_enable"