diff --git a/app/src/main/assets/pl-changelog.html b/app/src/main/assets/pl-changelog.html
index a8944f04..70dd9bea 100644
--- a/app/src/main/assets/pl-changelog.html
+++ b/app/src/main/assets/pl-changelog.html
@@ -1,8 +1,6 @@
-<h3>Wersja 4.3.1, 2020-08-27</h3>
+<h3>Wersja 4.4, 2020-08-27</h3>
 <ul>
-    <li>Dodana opcja automatycznej archiwizacji profilu na nowy rok szkolny.</li>
-    <li>Poprawione problemy z synchronizacją oraz mieszaniem się danych.</li>
-    <li>Przywrócona synchronizacja w wakacje.</li>
+    <li>Poprawione komunikaty o aktualizacjach aplikacji.</li>
 </ul>
 <br>
 <br>
diff --git a/app/src/main/cpp/szkolny-signing.cpp b/app/src/main/cpp/szkolny-signing.cpp
index 8e1f92dd..a66cabf6 100644
--- a/app/src/main/cpp/szkolny-signing.cpp
+++ b/app/src/main/cpp/szkolny-signing.cpp
@@ -9,7 +9,7 @@
 
 /*secret password - removed for source code publication*/
 static toys AES_IV[16] = {
-	0x24, 0x85, 0x31, 0x5b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff  };
+	0x85, 0xd2, 0x0d, 0x9e, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff  };
 
 unsigned char *agony(unsigned int laugh, unsigned char *box, unsigned char *heat);
 
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/MainActivity.kt b/app/src/main/java/pl/szczodrzynski/edziennik/MainActivity.kt
index 3932ce3b..e1fe3b0c 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/MainActivity.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/MainActivity.kt
@@ -41,6 +41,8 @@ import pl.droidsonroids.gif.GifDrawable
 import pl.szczodrzynski.edziennik.data.api.edziennik.EdziennikTask
 import pl.szczodrzynski.edziennik.data.api.events.*
 import pl.szczodrzynski.edziennik.data.api.models.ApiError
+import pl.szczodrzynski.edziennik.data.api.szkolny.SzkolnyApi
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
 import pl.szczodrzynski.edziennik.data.db.entity.LoginStore
 import pl.szczodrzynski.edziennik.data.db.entity.Metadata.*
 import pl.szczodrzynski.edziennik.data.db.entity.Profile
@@ -48,7 +50,9 @@ import pl.szczodrzynski.edziennik.databinding.ActivitySzkolnyBinding
 import pl.szczodrzynski.edziennik.sync.AppManagerDetectedEvent
 import pl.szczodrzynski.edziennik.sync.SyncWorker
 import pl.szczodrzynski.edziennik.sync.UpdateWorker
+import pl.szczodrzynski.edziennik.ui.dialogs.RegisterUnavailableDialog
 import pl.szczodrzynski.edziennik.ui.dialogs.ServerMessageDialog
+import pl.szczodrzynski.edziennik.ui.dialogs.UpdateAvailableDialog
 import pl.szczodrzynski.edziennik.ui.dialogs.changelog.ChangelogDialog
 import pl.szczodrzynski.edziennik.ui.dialogs.event.EventManualDialog
 import pl.szczodrzynski.edziennik.ui.dialogs.settings.ProfileRemoveDialog
@@ -438,7 +442,7 @@ class MainActivity : AppCompatActivity(), CoroutineScope {
         })
 
         b.swipeRefreshLayout.isEnabled = true
-        b.swipeRefreshLayout.setOnRefreshListener { this.syncCurrentFeature() }
+        b.swipeRefreshLayout.setOnRefreshListener { launch { syncCurrentFeature() } }
         b.swipeRefreshLayout.setColorSchemeResources(
                 R.color.md_blue_500,
                 R.color.md_amber_500,
@@ -604,7 +608,7 @@ class MainActivity : AppCompatActivity(), CoroutineScope {
          |_____/ \__, |_| |_|\___|
                   __/ |
                  |__*/
-    fun syncCurrentFeature() {
+    suspend fun syncCurrentFeature() {
         if (app.profile.archived) {
             MaterialAlertDialogBuilder(this)
                     .setTitle(R.string.profile_archived_title)
@@ -640,6 +644,30 @@ class MainActivity : AppCompatActivity(), CoroutineScope {
             swipeRefreshLayout.isRefreshing = false
             return
         }
+
+        app.profile.registerName?.let { registerName ->
+            var status = app.config.sync.registerAvailability[registerName]
+            if (status == null || status.nextCheck < currentTimeUnix()) {
+                withContext(Dispatchers.IO) {
+                    val api = SzkolnyApi(app)
+                    api.runCatching(this@MainActivity) {
+                        val availability = getRegisterAvailability()
+                        app.config.sync.registerAvailability = availability
+                        status = availability[registerName]
+                    }
+                }
+            }
+
+            if (status?.available != true
+                    || status?.minVersionCode ?: BuildConfig.VERSION_CODE > BuildConfig.VERSION_CODE) {
+                swipeRefreshLayout.isRefreshing = false
+                loadTarget(DRAWER_ITEM_HOME)
+                if (status != null)
+                    RegisterUnavailableDialog(this, status!!)
+                return
+            }
+        }
+
         swipeRefreshLayout.isRefreshing = true
         Toast.makeText(this, fragmentToSyncName(navTargetId), Toast.LENGTH_SHORT).show()
         val fragmentParam = when (navTargetId) {
@@ -656,6 +684,20 @@ class MainActivity : AppCompatActivity(), CoroutineScope {
                 arguments = arguments
         ).enqueue(this)
     }
+    @Subscribe(threadMode = ThreadMode.MAIN, sticky = true)
+    fun onUpdateEvent(event: Update) {
+        EventBus.getDefault().removeStickyEvent(event)
+        UpdateAvailableDialog(this, event)
+    }
+    @Subscribe(threadMode = ThreadMode.MAIN, sticky = true)
+    fun onRegisterAvailabilityEvent(event: RegisterAvailabilityEvent) {
+        EventBus.getDefault().removeStickyEvent(event)
+        app.profile.registerName?.let { registerName ->
+            event.data[registerName]?.let {
+                RegisterUnavailableDialog(this, it)
+            }
+        }
+    }
     @Subscribe(threadMode = ThreadMode.MAIN)
     fun onApiTaskStartedEvent(event: ApiTaskStartedEvent) {
         swipeRefreshLayout.isRefreshing = true
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/config/ConfigSync.kt b/app/src/main/java/pl/szczodrzynski/edziennik/config/ConfigSync.kt
index a6bb68df..2d7dcf78 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/config/ConfigSync.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/config/ConfigSync.kt
@@ -4,12 +4,18 @@
 
 package pl.szczodrzynski.edziennik.config
 
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
 import pl.szczodrzynski.edziennik.config.utils.get
 import pl.szczodrzynski.edziennik.config.utils.getIntList
 import pl.szczodrzynski.edziennik.config.utils.set
+import pl.szczodrzynski.edziennik.config.utils.setMap
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus
 import pl.szczodrzynski.edziennik.utils.models.Time
 
 class ConfigSync(private val config: Config) {
+    private val gson = Gson()
+
     private var mDontShowAppManagerDialog: Boolean? = null
     var dontShowAppManagerDialog: Boolean
         get() { mDontShowAppManagerDialog = mDontShowAppManagerDialog ?: config.values.get("dontShowAppManagerDialog", false); return mDontShowAppManagerDialog ?: false }
@@ -106,4 +112,9 @@ class ConfigSync(private val config: Config) {
     var tokenVulcanList: List<Int>
         get() { mTokenVulcanList = mTokenVulcanList ?: config.values.getIntList("tokenVulcanList", listOf()); return mTokenVulcanList ?: listOf() }
         set(value) { config.set("tokenVulcanList", value); mTokenVulcanList = value }
+
+    private var mRegisterAvailability: Map<String, RegisterAvailabilityStatus>? = null
+    var registerAvailability: Map<String, RegisterAvailabilityStatus>
+        get() { mRegisterAvailability = mRegisterAvailability ?: config.values.get("registerAvailability", null as String?)?.let { it -> gson.fromJson<Map<String, RegisterAvailabilityStatus>>(it, object: TypeToken<Map<String, RegisterAvailabilityStatus>>(){}.type) }; return mRegisterAvailability ?: mapOf() }
+        set(value) { config.setMap("registerAvailability", value); mRegisterAvailability = value }
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
index 1188b1a4..c98cf832 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/config/utils/ConfigExtensions.kt
@@ -49,6 +49,9 @@ fun AbstractConfig.setIntList(key: String, value: List<Int>?) {
 fun AbstractConfig.setLongList(key: String, value: List<Long>?) {
     set(key, value?.let { gson.toJson(it) })
 }
+fun <K, V> AbstractConfig.setMap(key: String, value: Map<K, V>?) {
+    set(key, value?.let { gson.toJson(it) })
+}
 
 fun HashMap<String, String?>.get(key: String, default: String?): String? {
     return this[key] ?: default
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/EdziennikTask.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/EdziennikTask.kt
index e1a830b5..aa316948 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/EdziennikTask.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/edziennik/EdziennikTask.kt
@@ -5,8 +5,8 @@
 package pl.szczodrzynski.edziennik.data.api.edziennik
 
 import com.google.gson.JsonObject
-import pl.szczodrzynski.edziennik.App
-import pl.szczodrzynski.edziennik.R
+import org.greenrobot.eventbus.EventBus
+import pl.szczodrzynski.edziennik.*
 import pl.szczodrzynski.edziennik.data.api.*
 import pl.szczodrzynski.edziennik.data.api.edziennik.edudziennik.Edudziennik
 import pl.szczodrzynski.edziennik.data.api.edziennik.idziennik.Idziennik
@@ -15,9 +15,11 @@ import pl.szczodrzynski.edziennik.data.api.edziennik.mobidziennik.Mobidziennik
 import pl.szczodrzynski.edziennik.data.api.edziennik.podlasie.Podlasie
 import pl.szczodrzynski.edziennik.data.api.edziennik.template.Template
 import pl.szczodrzynski.edziennik.data.api.edziennik.vulcan.Vulcan
+import pl.szczodrzynski.edziennik.data.api.events.RegisterAvailabilityEvent
 import pl.szczodrzynski.edziennik.data.api.interfaces.EdziennikCallback
 import pl.szczodrzynski.edziennik.data.api.interfaces.EdziennikInterface
 import pl.szczodrzynski.edziennik.data.api.models.ApiError
+import pl.szczodrzynski.edziennik.data.api.szkolny.SzkolnyApi
 import pl.szczodrzynski.edziennik.data.api.task.IApiTask
 import pl.szczodrzynski.edziennik.data.db.entity.LoginStore
 import pl.szczodrzynski.edziennik.data.db.entity.Profile
@@ -88,6 +90,33 @@ open class EdziennikTask(override val profileId: Int, val request: Any) : IApiTa
                 taskCallback.onCompleted()
                 return
             }
+
+            profile.registerName?.let { registerName ->
+                var status = app.config.sync.registerAvailability[registerName]
+                if (status == null || status.nextCheck < currentTimeUnix()) {
+                    val api = SzkolnyApi(app)
+                    api.runCatching({
+                        val availability = getRegisterAvailability()
+                        app.config.sync.registerAvailability = availability
+                        status = availability[registerName]
+                    }, onError = {
+                        taskCallback.onError(it.toApiError(TAG))
+                        return
+                    })
+                }
+
+                if (status?.available != true
+                        || status?.minVersionCode ?: BuildConfig.VERSION_CODE > BuildConfig.VERSION_CODE) {
+                    if (EventBus.getDefault().hasSubscriberForEvent(RegisterAvailabilityEvent::class.java)) {
+                        EventBus.getDefault().postSticky(
+                                RegisterAvailabilityEvent(app.config.sync.registerAvailability)
+                        )
+                    }
+                    cancel()
+                    taskCallback.onCompleted()
+                    return
+                }
+            }
         }
 
         edziennikInterface = when (loginStore.type) {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/events/RegisterAvailabilityEvent.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/events/RegisterAvailabilityEvent.kt
new file mode 100644
index 00000000..fe66c4b3
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/events/RegisterAvailabilityEvent.kt
@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-9-3.
+ */
+
+package pl.szczodrzynski.edziennik.data.api.events
+
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus
+
+data class RegisterAvailabilityEvent(
+        val data: Map< String, RegisterAvailabilityStatus>
+)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyApi.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyApi.kt
index d2b4df70..042e63fe 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyApi.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyApi.kt
@@ -12,12 +12,14 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
+import org.greenrobot.eventbus.EventBus
 import pl.szczodrzynski.edziennik.*
 import pl.szczodrzynski.edziennik.data.api.szkolny.adapter.DateAdapter
 import pl.szczodrzynski.edziennik.data.api.szkolny.adapter.TimeAdapter
 import pl.szczodrzynski.edziennik.data.api.szkolny.interceptor.SignatureInterceptor
 import pl.szczodrzynski.edziennik.data.api.szkolny.request.*
 import pl.szczodrzynski.edziennik.data.api.szkolny.response.ApiResponse
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus
 import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
 import pl.szczodrzynski.edziennik.data.api.szkolny.response.WebPushResponse
 import pl.szczodrzynski.edziennik.data.db.entity.Event
@@ -112,6 +114,22 @@ class SzkolnyApi(val app: App) : CoroutineScope {
      */
     @Throws(Exception::class)
     private inline fun <reified T> parseResponse(response: Response<ApiResponse<T>>): T {
+        app.config.update = response.body()?.update?.let { update ->
+            if (update.versionCode > BuildConfig.VERSION_CODE) {
+                if (update.updateMandatory
+                        && EventBus.getDefault().hasSubscriberForEvent(update::class.java)) {
+                    EventBus.getDefault().postSticky(update)
+                }
+                update
+            }
+            else
+                null
+        }
+
+        response.body()?.registerAvailability?.let { registerAvailability ->
+            app.config.sync.registerAvailability = registerAvailability
+        }
+
         if (response.isSuccessful && response.body()?.success == true) {
             if (Unit is T) {
                 return Unit
@@ -341,4 +359,10 @@ class SzkolnyApi(val app: App) : CoroutineScope {
         val response = api.firebaseToken(registerName).execute()
         return parseResponse(response)
     }
+
+    @Throws(Exception::class)
+    fun getRegisterAvailability(): Map<String, RegisterAvailabilityStatus> {
+        val response = api.registerAvailability().execute()
+        return parseResponse(response)
+    }
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyService.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyService.kt
index 401d8886..6046e4da 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyService.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/SzkolnyService.kt
@@ -38,4 +38,7 @@ interface SzkolnyService {
 
     @GET("firebase/token/{registerName}")
     fun firebaseToken(@Path("registerName") registerName: String): Call<ApiResponse<String>>
+
+    @GET("registerAvailability")
+    fun registerAvailability(): Call<ApiResponse<Map<String, RegisterAvailabilityStatus>>>
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
index 877bc0c9..67e8310a 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/interceptor/Signing.kt
@@ -46,6 +46,6 @@ object Signing {
 
     /*fun provideKey(param1: String, param2: Long): ByteArray {*/
     fun pleaseStopRightNow(param1: String, param2: Long): ByteArray {
-        return "$param1.MTIzNDU2Nzg5MDiVEOFGvG===.$param2".sha256()
+        return "$param1.MTIzNDU2Nzg5MDSA64wjse===.$param2".sha256()
     }
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/ApiResponse.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/ApiResponse.kt
index ac56f53f..0987dcef 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/ApiResponse.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/ApiResponse.kt
@@ -10,7 +10,10 @@ data class ApiResponse<T> (
 
     val errors: List<Error>? = null,
 
-    val data: T? = null
+    val data: T? = null,
+
+    val update: Update? = null,
+    val registerAvailability: Map<String, RegisterAvailabilityStatus>? = null
 ) {
     data class Error (val code: String, val reason: String)
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/RegisterAvailabilityStatus.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/RegisterAvailabilityStatus.kt
new file mode 100644
index 00000000..0596a8ac
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/RegisterAvailabilityStatus.kt
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-9-2.
+ */
+
+package pl.szczodrzynski.edziennik.data.api.szkolny.response
+
+import pl.szczodrzynski.edziennik.BuildConfig
+import pl.szczodrzynski.edziennik.DAY
+import pl.szczodrzynski.edziennik.currentTimeUnix
+
+data class RegisterAvailabilityStatus(
+        val available: Boolean,
+        val name: String?,
+        val message: Message?,
+        val nextCheck: Long = currentTimeUnix() + 7 * DAY,
+        val minVersionCode: Int = BuildConfig.VERSION_CODE
+) {
+    data class Message(
+            val title: String,
+            val contentShort: String,
+            val contentLong: String,
+            val icon: String?,
+            val image: String?,
+            val url: String?
+    )
+}
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/UpdateResponse.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/UpdateResponse.kt
index a2028926..63a8ce9d 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/UpdateResponse.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/api/szkolny/response/UpdateResponse.kt
@@ -11,5 +11,6 @@ data class Update(
         val releaseNotes: String?,
         val releaseType: String,
         val isOnGooglePlay: Boolean,
-        val downloadUrl: String?
-)
\ No newline at end of file
+        val downloadUrl: String?,
+        val updateMandatory: Boolean
+)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
index 0dbb8502..997e845b 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/entity/Profile.kt
@@ -16,8 +16,7 @@ import androidx.room.Ignore
 import com.google.gson.JsonObject
 import pl.droidsonroids.gif.GifDrawable
 import pl.szczodrzynski.edziennik.*
-import pl.szczodrzynski.edziennik.data.api.LOGIN_TYPE_EDUDZIENNIK
-import pl.szczodrzynski.edziennik.data.api.LOGIN_TYPE_PODLASIE
+import pl.szczodrzynski.edziennik.data.api.*
 import pl.szczodrzynski.edziennik.utils.ProfileImageHolder
 import pl.szczodrzynski.edziennik.utils.models.Date
 import pl.szczodrzynski.navlib.ImageHolder
@@ -128,6 +127,17 @@ open class Profile(
     val isParent
         get() = accountName != null
 
+    val registerName
+        get() = when (loginStoreType) {
+            LOGIN_TYPE_LIBRUS -> "librus"
+            LOGIN_TYPE_VULCAN -> "vulcan"
+            LOGIN_TYPE_IDZIENNIK -> "idziennik"
+            LOGIN_TYPE_MOBIDZIENNIK -> "mobidziennik"
+            LOGIN_TYPE_PODLASIE -> "podlasie"
+            LOGIN_TYPE_EDUDZIENNIK -> "edudziennik"
+            else -> null
+        }
+
     override fun getImageDrawable(context: Context): Drawable {
         if (archived) {
             return context.getDrawableFromRes(pl.szczodrzynski.edziennik.R.drawable.profile_archived).also {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/firebase/SzkolnyAppFirebase.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/firebase/SzkolnyAppFirebase.kt
index 2ebb8c66..1d563c34 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/firebase/SzkolnyAppFirebase.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/firebase/SzkolnyAppFirebase.kt
@@ -5,10 +5,13 @@
 package pl.szczodrzynski.edziennik.data.firebase
 
 import com.google.gson.JsonParser
+import com.google.gson.reflect.TypeToken
 import kotlinx.coroutines.*
 import org.greenrobot.eventbus.EventBus
 import pl.szczodrzynski.edziennik.*
 import pl.szczodrzynski.edziennik.data.api.events.FeedbackMessageEvent
+import pl.szczodrzynski.edziennik.data.api.events.RegisterAvailabilityEvent
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus
 import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
 import pl.szczodrzynski.edziennik.data.api.task.PostNotifications
 import pl.szczodrzynski.edziennik.data.db.entity.*
@@ -50,6 +53,16 @@ class SzkolnyAppFirebase(val app: App, val profiles: List<Profile>, val message:
                     val message = app.gson.fromJson(message.data.getString("message"), FeedbackMessage::class.java) ?: return@launch
                     feedbackMessage(message)
                 }
+                "registerAvailability" -> launch {
+                    val data = app.gson.fromJson<Map<String, RegisterAvailabilityStatus>>(
+                            message.data.getString("registerAvailability"),
+                            object: TypeToken<Map<String, RegisterAvailabilityStatus>>(){}.type
+                    ) ?: return@launch
+                    app.config.sync.registerAvailability = data
+                    if (EventBus.getDefault().hasSubscriberForEvent(RegisterAvailabilityEvent::class.java)) {
+                        EventBus.getDefault().postSticky(RegisterAvailabilityEvent(data))
+                    }
+                }
             }
         }
     }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt b/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
index 377ab806..80e21e6b 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/sync/UpdateWorker.kt
@@ -14,6 +14,7 @@ import android.widget.Toast
 import androidx.core.app.NotificationCompat
 import androidx.work.*
 import kotlinx.coroutines.*
+import org.greenrobot.eventbus.EventBus
 import pl.szczodrzynski.edziennik.*
 import pl.szczodrzynski.edziennik.R
 import pl.szczodrzynski.edziennik.data.api.szkolny.SzkolnyApi
@@ -76,7 +77,7 @@ class UpdateWorker(val context: Context, val params: WorkerParameters) : Worker(
             try {
                 val update = overrideUpdate
                         ?: run {
-                            val updates = withContext(Dispatchers.Default) {
+                            withContext(Dispatchers.Default) {
                                 SzkolnyApi(app).runCatching({
                                     getUpdate("beta")
                                 }, {
@@ -84,15 +85,25 @@ class UpdateWorker(val context: Context, val params: WorkerParameters) : Worker(
                                 })
                             } ?: return@run null
 
-                            if (updates.isEmpty()) {
+                            if (app.config.update == null
+                                    || app.config.update?.versionCode ?: BuildConfig.VERSION_CODE <= BuildConfig.VERSION_CODE) {
                                 app.config.update = null
                                 Toast.makeText(app, app.getString(R.string.notification_no_update), Toast.LENGTH_SHORT).show()
                                 return@run null
                             }
-                            updates[0]
+                            app.config.update
                         } ?: return
 
-                app.config.update = update
+                if (update.versionCode <= BuildConfig.VERSION_CODE) {
+                    app.config.update = null
+                    return
+                }
+
+                if (EventBus.getDefault().hasSubscriberForEvent(update::class.java)) {
+                    if (!update.updateMandatory) // mandatory updates are posted by the SzkolnyApi
+                        EventBus.getDefault().postSticky(update)
+                    return
+                }
 
                 val notificationIntent = Intent(app, UpdateDownloaderService::class.java)
                 val pendingIntent = PendingIntent.getService(app, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT)
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/RegisterUnavailableDialog.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/RegisterUnavailableDialog.kt
new file mode 100644
index 00000000..de698c5a
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/RegisterUnavailableDialog.kt
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-9-3.
+ */
+
+package pl.szczodrzynski.edziennik.ui.dialogs
+
+import android.view.LayoutInflater
+import androidx.appcompat.app.AlertDialog
+import androidx.appcompat.app.AppCompatActivity
+import coil.api.load
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import pl.szczodrzynski.edziennik.App
+import pl.szczodrzynski.edziennik.BuildConfig
+import pl.szczodrzynski.edziennik.R
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus
+import pl.szczodrzynski.edziennik.databinding.DialogRegisterUnavailableBinding
+import pl.szczodrzynski.edziennik.onClick
+import pl.szczodrzynski.edziennik.utils.Utils
+import kotlin.coroutines.CoroutineContext
+
+class RegisterUnavailableDialog(
+        val activity: AppCompatActivity,
+        val status: RegisterAvailabilityStatus,
+        val onShowListener: ((tag: String) -> Unit)? = null,
+        val onDismissListener: ((tag: String) -> Unit)? = null
+) : CoroutineScope {
+    companion object {
+        private const val TAG = "RegisterUnavailableDialog"
+    }
+
+    private lateinit var app: App
+    private lateinit var dialog: AlertDialog
+
+    private val job = Job()
+    override val coroutineContext: CoroutineContext
+        get() = job + Dispatchers.Main
+
+    init { run {
+        if (activity.isFinishing)
+            return@run
+        if (status.available && status.minVersionCode <= BuildConfig.VERSION_CODE)
+            return@run
+        onShowListener?.invoke(TAG)
+        app = activity.applicationContext as App
+
+        if (!status.available && status.message != null) {
+            val b = DialogRegisterUnavailableBinding.inflate(LayoutInflater.from(activity), null, false)
+            b.message = status.message
+            if (status.message.image != null)
+                b.image.load(status.message.image)
+            if (status.message.url != null) {
+                b.readMore.onClick {
+                    Utils.openUrl(activity, status.message.url)
+                }
+            }
+            dialog = MaterialAlertDialogBuilder(activity)
+                    .setView(b.root)
+                    .setPositiveButton(R.string.close) { dialog, _ ->
+                        dialog.dismiss()
+                    }
+                    .setOnDismissListener {
+                        onDismissListener?.invoke(TAG)
+                    }
+                    .show()
+        }
+
+        val update = app.config.update
+        if (status.minVersionCode > BuildConfig.VERSION_CODE) {
+            if (update != null && update.versionCode >= status.minVersionCode) {
+                UpdateAvailableDialog(activity, update, true, onShowListener, onDismissListener)
+            }
+            else {
+                // this *should* never happen
+                dialog = MaterialAlertDialogBuilder(activity)
+                        .setTitle(R.string.update_available_title)
+                        .setMessage(R.string.update_available_fallback)
+                        .setPositiveButton(R.string.update_available_button) { dialog, _ ->
+                            Utils.openGooglePlay(activity)
+                            dialog.dismiss()
+                        }
+                        .setCancelable(false)
+                        .setOnDismissListener {
+                            onDismissListener?.invoke(TAG)
+                        }
+                        .show()
+            }
+            return@run
+        }
+    }}
+}
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/ServerMessageDialog.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/ServerMessageDialog.kt
index 27d11dad..cebc4e04 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/ServerMessageDialog.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/ServerMessageDialog.kt
@@ -17,7 +17,7 @@ import kotlin.coroutines.CoroutineContext
 class ServerMessageDialog(
         val activity: AppCompatActivity,
         val title: String,
-        val message: String,
+        val message: CharSequence,
         val onShowListener: ((tag: String) -> Unit)? = null,
         val onDismissListener: ((tag: String) -> Unit)? = null
 ) : CoroutineScope {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/UpdateAvailableDialog.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/UpdateAvailableDialog.kt
new file mode 100644
index 00000000..6446170b
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/dialogs/UpdateAvailableDialog.kt
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-9-3.
+ */
+
+package pl.szczodrzynski.edziennik.ui.dialogs
+
+import android.text.Html
+import androidx.appcompat.app.AlertDialog
+import androidx.appcompat.app.AppCompatActivity
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import pl.szczodrzynski.edziennik.*
+import pl.szczodrzynski.edziennik.data.api.szkolny.response.Update
+import pl.szczodrzynski.edziennik.sync.UpdateDownloaderService
+import kotlin.coroutines.CoroutineContext
+
+class UpdateAvailableDialog(
+        val activity: AppCompatActivity,
+        val update: Update,
+        val mandatory: Boolean = update.updateMandatory,
+        val onShowListener: ((tag: String) -> Unit)? = null,
+        val onDismissListener: ((tag: String) -> Unit)? = null
+) : CoroutineScope {
+    companion object {
+        private const val TAG = "UpdateAvailableDialog"
+    }
+
+    private lateinit var app: App
+    private lateinit var dialog: AlertDialog
+
+    private val job = Job()
+    override val coroutineContext: CoroutineContext
+        get() = job + Dispatchers.Main
+
+    init { run {
+        if (activity.isFinishing)
+            return@run
+        if (update.versionCode <= BuildConfig.VERSION_CODE)
+            return@run
+        onShowListener?.invoke(TAG)
+        app = activity.applicationContext as App
+
+        dialog = MaterialAlertDialogBuilder(activity)
+                .setTitle(R.string.update_available_title)
+                .setMessage(
+                        R.string.update_available_format,
+                        BuildConfig.VERSION_NAME,
+                        update.versionName,
+                        update.releaseNotes?.let { Html.fromHtml(it) } ?: "---"
+                )
+                .setPositiveButton(R.string.update_available_button) { dialog, _ ->
+                    activity.startService(Intent(app, UpdateDownloaderService::class.java))
+                    dialog.dismiss()
+                }
+                .also {
+                    if (!mandatory)
+                        it.setNeutralButton(R.string.update_available_later, null)
+                }
+                .setCancelable(!mandatory)
+                .setOnDismissListener {
+                    onDismissListener?.invoke(TAG)
+                }
+                .show()
+    }}
+}
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/CardItemTouchHelperCallback.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/CardItemTouchHelperCallback.kt
index 34621474..7cfb3c2f 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/CardItemTouchHelperCallback.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/CardItemTouchHelperCallback.kt
@@ -33,9 +33,10 @@ class CardItemTouchHelperCallback(private val cardAdapter: HomeCardAdapter, priv
     }
 
     override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
-        removeCard(viewHolder.adapterPosition, cardAdapter)
-        cardAdapter.items.removeAt(viewHolder.adapterPosition)
-        cardAdapter.notifyItemRemoved(viewHolder.adapterPosition)
+        val position = viewHolder.adapterPosition
+        removeCard(position, cardAdapter)
+        cardAdapter.items.removeAt(position)
+        cardAdapter.notifyItemRemoved(position)
     }
 
     override fun onSelectedChanged(viewHolder: RecyclerView.ViewHolder?, actionState: Int) {
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/HomeFragment.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/HomeFragment.kt
index 8d276a82..1b53e826 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/HomeFragment.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/HomeFragment.kt
@@ -21,12 +21,9 @@ import androidx.recyclerview.widget.RecyclerViewAccessibilityDelegate
 import com.mikepenz.iconics.typeface.library.community.material.CommunityMaterial.Icon
 import com.mikepenz.iconics.typeface.library.szkolny.font.SzkolnyFont
 import kotlinx.coroutines.*
-import pl.szczodrzynski.edziennik.App
-import pl.szczodrzynski.edziennik.MainActivity
-import pl.szczodrzynski.edziennik.R
+import pl.szczodrzynski.edziennik.*
 import pl.szczodrzynski.edziennik.data.db.entity.LoginStore
 import pl.szczodrzynski.edziennik.databinding.FragmentHomeBinding
-import pl.szczodrzynski.edziennik.onClick
 import pl.szczodrzynski.edziennik.ui.dialogs.home.StudentNumberDialog
 import pl.szczodrzynski.edziennik.ui.modules.home.cards.*
 import pl.szczodrzynski.edziennik.utils.Themes
@@ -50,9 +47,11 @@ class HomeFragment : Fragment(), CoroutineScope {
             cardAdapter.notifyItemMoved(fromPosition, toPosition)
 
             val homeCards = App.config.forProfile().ui.homeCards.toMutableList()
-            val fromPair = homeCards[fromPosition]
-            homeCards[fromPosition] = homeCards[toPosition]
-            homeCards[toPosition] = fromPair
+            val fromIndex = homeCards.indexOfFirst { it.cardId == fromCard.id }
+            val toIndex = homeCards.indexOfFirst { it.cardId == toCard.id }
+            val fromPair = homeCards[fromIndex]
+            homeCards[fromIndex] = homeCards[toIndex]
+            homeCards[toIndex] = fromPair
             App.config.forProfile().ui.homeCards = homeCards
             return true
         }
@@ -64,10 +63,10 @@ class HomeFragment : Fragment(), CoroutineScope {
             val card = cardAdapter.items[position]
             if (card.id >= 100) {
                 // debug & archive cards are not removable
-                cardAdapter.notifyDataSetChanged()
+                //cardAdapter.notifyDataSetChanged()
                 return
             }
-            homeCards.removeAt(position)
+            homeCards.removeAll { it.cardId == card.id }
             App.config.forProfile().ui.homeCards = homeCards
         }
     }
@@ -166,6 +165,13 @@ class HomeFragment : Fragment(), CoroutineScope {
         if (app.profile.archived)
             items.add(0, HomeArchiveCard(101, app, activity, this, app.profile))
 
+        val status = app.config.sync.registerAvailability[app.profile.registerName]
+        val update = app.config.update
+        if (update != null && update.versionCode > BuildConfig.VERSION_CODE
+                || status != null && (!status.available || status.minVersionCode > BuildConfig.VERSION_CODE)) {
+            items.add(0, HomeAvailabilityCard(102, app, activity, this, app.profile))
+        }
+
         val adapter = HomeCardAdapter(items)
         val itemTouchHelper = ItemTouchHelper(CardItemTouchHelperCallback(adapter, b.refreshLayout))
         adapter.itemTouchHelper = itemTouchHelper
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/cards/HomeAvailabilityCard.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/cards/HomeAvailabilityCard.kt
new file mode 100644
index 00000000..26c8d609
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/home/cards/HomeAvailabilityCard.kt
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2020-9-3.
+ */
+
+package pl.szczodrzynski.edziennik.ui.modules.home.cards
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.FrameLayout
+import androidx.core.view.isVisible
+import androidx.core.view.plusAssign
+import androidx.core.view.setMargins
+import coil.api.load
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import pl.szczodrzynski.edziennik.*
+import pl.szczodrzynski.edziennik.data.db.entity.Profile
+import pl.szczodrzynski.edziennik.databinding.CardHomeAvailabilityBinding
+import pl.szczodrzynski.edziennik.sync.UpdateDownloaderService
+import pl.szczodrzynski.edziennik.ui.dialogs.RegisterUnavailableDialog
+import pl.szczodrzynski.edziennik.ui.dialogs.UpdateAvailableDialog
+import pl.szczodrzynski.edziennik.ui.modules.home.HomeCard
+import pl.szczodrzynski.edziennik.ui.modules.home.HomeCardAdapter
+import pl.szczodrzynski.edziennik.ui.modules.home.HomeFragment
+import kotlin.coroutines.CoroutineContext
+
+class HomeAvailabilityCard(
+        override val id: Int,
+        val app: App,
+        val activity: MainActivity,
+        val fragment: HomeFragment,
+        val profile: Profile
+) : HomeCard, CoroutineScope {
+    companion object {
+        private const val TAG = "HomeAvailabilityCard"
+    }
+
+    private var job: Job = Job()
+    override val coroutineContext: CoroutineContext
+        get() = job + Dispatchers.Main
+
+    override fun bind(position: Int, holder: HomeCardAdapter.ViewHolder) {
+        holder.root.removeAllViews()
+        val b = CardHomeAvailabilityBinding.inflate(LayoutInflater.from(holder.root.context))
+        b.root.layoutParams = FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT).apply {
+            setMargins(8.dp)
+        }
+        holder.root += b.root
+
+        val status = app.config.sync.registerAvailability[profile.registerName]
+        val update = app.config.update
+
+        if (update == null && status == null)
+            return
+
+        var onInfoClick = { _: View -> }
+
+        if (status != null && !status.available && status.message != null) {
+            b.homeAvailabilityTitle.text = status.message.title
+            b.homeAvailabilityText.text = status.message.contentShort
+            b.homeAvailabilityUpdate.isVisible = false
+            b.homeAvailabilityIcon.setImageResource(R.drawable.ic_sync)
+            if (status.message.icon != null)
+                b.homeAvailabilityIcon.load(status.message.icon)
+            onInfoClick = {
+                RegisterUnavailableDialog(activity, status)
+            }
+        }
+        else if (update != null && update.versionCode > BuildConfig.VERSION_CODE) {
+            b.homeAvailabilityTitle.setText(R.string.home_availability_title)
+            b.homeAvailabilityText.setText(R.string.home_availability_text, update.versionName)
+            b.homeAvailabilityUpdate.isVisible = true
+            b.homeAvailabilityIcon.setImageResource(R.drawable.ic_update)
+            onInfoClick = {
+                UpdateAvailableDialog(activity, update)
+            }
+        }
+
+        b.homeAvailabilityUpdate.onClick {
+            if (update == null)
+                return@onClick
+            activity.startService(Intent(app, UpdateDownloaderService::class.java))
+        }
+
+        b.homeAvailabilityInfo.onClick(onInfoClick)
+        holder.root.onClick(onInfoClick)
+    }
+
+    override fun unbind(position: Int, holder: HomeCardAdapter.ViewHolder) = Unit
+}
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginChooserFragment.kt b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginChooserFragment.kt
index c25b07d1..90945294 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginChooserFragment.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/ui/modules/login/LoginChooserFragment.kt
@@ -13,14 +13,12 @@ import android.view.ViewGroup
 import androidx.core.view.isVisible
 import androidx.fragment.app.Fragment
 import androidx.recyclerview.widget.LinearLayoutManager
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.Job
-import pl.szczodrzynski.edziennik.App
-import pl.szczodrzynski.edziennik.Bundle
-import pl.szczodrzynski.edziennik.R
+import kotlinx.coroutines.*
+import pl.szczodrzynski.edziennik.*
+import pl.szczodrzynski.edziennik.data.api.*
+import pl.szczodrzynski.edziennik.data.api.szkolny.SzkolnyApi
 import pl.szczodrzynski.edziennik.databinding.LoginChooserFragmentBinding
-import pl.szczodrzynski.edziennik.onClick
+import pl.szczodrzynski.edziennik.ui.dialogs.RegisterUnavailableDialog
 import pl.szczodrzynski.edziennik.ui.modules.feedback.FeedbackActivity
 import pl.szczodrzynski.edziennik.utils.SimpleDividerItemDecoration
 import kotlin.coroutines.CoroutineContext
@@ -53,18 +51,23 @@ class LoginChooserFragment : Fragment(), CoroutineScope {
         if (!isAdded) return
 
         val adapter = LoginChooserAdapter(activity) { loginType, loginMode ->
-            if (loginMode.isPlatformSelection) {
-                nav.navigate(R.id.loginPlatformListFragment, Bundle(
+            launch {
+                if (!checkAvailability(loginType.loginType))
+                    return@launch
+
+                if (loginMode.isPlatformSelection) {
+                    nav.navigate(R.id.loginPlatformListFragment, Bundle(
+                            "loginType" to loginType.loginType,
+                            "loginMode" to loginMode.loginMode
+                    ), activity.navOptions)
+                    return@launch
+                }
+
+                nav.navigate(R.id.loginFormFragment, Bundle(
                         "loginType" to loginType.loginType,
                         "loginMode" to loginMode.loginMode
                 ), activity.navOptions)
-                return@LoginChooserAdapter
             }
-
-            nav.navigate(R.id.loginFormFragment, Bundle(
-                    "loginType" to loginType.loginType,
-                    "loginMode" to loginMode.loginMode
-            ), activity.navOptions)
         }
 
         LoginInfo.chooserList = LoginInfo.chooserList
@@ -102,4 +105,35 @@ class LoginChooserFragment : Fragment(), CoroutineScope {
             }
         }
     }
+
+    private suspend fun checkAvailability(loginType: Int): Boolean {
+        when (loginType) {
+            LOGIN_TYPE_LIBRUS -> "librus"
+            LOGIN_TYPE_VULCAN -> "vulcan"
+            LOGIN_TYPE_IDZIENNIK -> "idziennik"
+            LOGIN_TYPE_MOBIDZIENNIK -> "mobidziennik"
+            LOGIN_TYPE_PODLASIE -> "podlasie"
+            LOGIN_TYPE_EDUDZIENNIK -> "edudziennik"
+            else -> null
+        }?.let { registerName ->
+            var status = app.config.sync.registerAvailability[registerName]
+            if (status == null || status.nextCheck < currentTimeUnix()) {
+                withContext(Dispatchers.IO) {
+                    val api = SzkolnyApi(app)
+                    api.runCatching(activity) {
+                        val availability = getRegisterAvailability()
+                        app.config.sync.registerAvailability = availability
+                        status = availability[registerName]
+                    }
+                }
+            }
+
+            if (status?.available != true) {
+                if (status != null)
+                    RegisterUnavailableDialog(activity, status!!)
+                return false
+            }
+        }
+        return true
+    }
 }
diff --git a/app/src/main/res/drawable/ic_update.xml b/app/src/main/res/drawable/ic_update.xml
new file mode 100644
index 00000000..e059b093
--- /dev/null
+++ b/app/src/main/res/drawable/ic_update.xml
@@ -0,0 +1,11 @@
+<!--
+  ~ Copyright (c) Kuba Szczodrzyński 2020-9-3.
+  -->
+
+<vector android:height="128dp" android:viewportHeight="64"
+    android:viewportWidth="64" android:width="128dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#1a6ee2" android:pathData="m29.583,48.966c1.329,1.347 3.505,1.347 4.834,0l10.917,-11.06c1.466,-1.484 0.353,-3.906 -1.795,-3.906h-5.539v-8.5c0,-1.375 -1.125,-2.5 -2.5,-2.5h-7c-1.375,0 -2.5,1.125 -2.5,2.5v8.5h-5.539c-2.147,0 -3.26,2.422 -1.795,3.906z"/>
+    <path android:fillColor="#2aa7ed" android:pathData="m28.5,12h7c1.375,0 2.5,-1.125 2.5,-2.5s-1.125,-2.5 -2.5,-2.5h-7c-1.375,0 -2.5,1.125 -2.5,2.5s1.125,2.5 2.5,2.5z"/>
+    <path android:fillColor="#2082e6" android:pathData="m28.5,20h7c1.375,0 2.5,-1.125 2.5,-2.5s-1.125,-2.5 -2.5,-2.5h-7c-1.375,0 -2.5,1.125 -2.5,2.5s1.125,2.5 2.5,2.5z"/>
+    <path android:fillColor="#1762df" android:pathData="m54,55.5c0,1.375 -1.125,2.5 -2.5,2.5h-39c-1.375,0 -2.5,-1.125 -2.5,-2.5s1.125,-2.5 2.5,-2.5h39c1.375,0 2.5,1.125 2.5,2.5z"/>
+</vector>
diff --git a/app/src/main/res/layout/card_home_availability.xml b/app/src/main/res/layout/card_home_availability.xml
new file mode 100644
index 00000000..9b4f67f5
--- /dev/null
+++ b/app/src/main/res/layout/card_home_availability.xml
@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (c) Kuba Szczodrzyński 2020-9-3.
+  -->
+
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center_vertical"
+        android:orientation="horizontal"
+        tools:layout_margin="8dp">
+
+        <LinearLayout
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:orientation="vertical">
+
+            <TextView
+                android:id="@+id/homeAvailabilityTitle"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/home_availability_title"
+                android:textAppearance="@style/NavView.TextView.Title" />
+
+            <androidx.appcompat.widget.AppCompatTextView
+                android:id="@+id/homeAvailabilityText"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_gravity="center_horizontal"
+                android:layout_margin="16dp"
+                android:fontFamily="sans-serif-light"
+                android:gravity="center_horizontal"
+                android:text="@string/home_availability_text"
+                android:textSize="16sp"
+                tools:text="Zaktualizuj aplikację do najnowszej wersji 4.3.1." />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/homeAvailabilityUpdate"
+                style="@style/Widget.MaterialComponents.Button"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/home_availability_update" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/homeAvailabilityInfo"
+                style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/home_availability_info" />
+        </LinearLayout>
+
+        <ImageView
+            android:id="@+id/homeAvailabilityIcon"
+            android:layout_width="64dp"
+            android:layout_height="64dp"
+            android:layout_marginStart="8dp"
+            android:layout_marginLeft="8dp"
+            app:srcCompat="@drawable/ic_update" />
+    </LinearLayout>
+</layout>
diff --git a/app/src/main/res/layout/dialog_register_unavailable.xml b/app/src/main/res/layout/dialog_register_unavailable.xml
new file mode 100644
index 00000000..2d395494
--- /dev/null
+++ b/app/src/main/res/layout/dialog_register_unavailable.xml
@@ -0,0 +1,72 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (c) Kuba Szczodrzyński 2020-9-3.
+  -->
+
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <data>
+        <import type="android.view.View" />
+        <import type="android.text.Html" />
+        <variable
+            name="message"
+            type="pl.szczodrzynski.edziennik.data.api.szkolny.response.RegisterAvailabilityStatus.Message" />
+    </data>
+
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <ImageView
+                android:id="@+id/image"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:adjustViewBounds="true"
+                android:scaleType="fitXY"
+                android:visibility="@{message.image != null ? View.VISIBLE : View.GONE}"
+                tools:src="@tools:sample/backgrounds/scenic" />
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical"
+                android:paddingLeft="24dp"
+                android:paddingTop="16dp"
+                android:paddingRight="24dp"
+                android:paddingBottom="16dp">
+
+                <TextView
+                    android:id="@+id/title"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:text="@{message.title}"
+                    android:textAppearance="@style/NavView.TextView.Title"
+                    tools:text="Dziennik nie działa" />
+
+                <TextView
+                    android:id="@+id/text"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="8dp"
+                    android:text="@{Html.fromHtml(message.contentLong)}"
+                    tools:text="Dziennik się zepsuł i nie działa, szkoda\n\n\nwiele linijek ma ten tekst" />
+
+                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/readMore"
+                    style="@style/Widget.MaterialComponents.Button"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_gravity="center_horizontal"
+                    android:layout_marginTop="16dp"
+                    android:text="@string/register_unavailable_read_more"
+                    android:visibility="@{message.url != null ? View.VISIBLE : View.GONE}" />
+            </LinearLayout>
+        </LinearLayout>
+    </ScrollView>
+</layout>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 60874690..d3f1ba4e 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1368,4 +1368,14 @@
     <string name="home_archive_close_no_target_title">Brak aktualnego profilu</string>
     <string name="home_archive_close_no_target_text">Uczeń %s nie posiada profilu na tym koncie w aktualnym roku szkolnym. Prawdopodobnie ten profil został usunięty lub uczeń nie uczęszcza już do tej klasy.\n\nAby przejść do aktualnego profilu, wybierz ucznia z listy lub zaloguj się na jego konto przyciskiem Dodaj ucznia.</string>
     <string name="login_copyright_notice">Znaki towarowe zamieszczone w tej aplikacji należą do ich prawowitych właścicieli i są używane wyłącznie w celach informacyjnych.</string>
+    <string name="update_available_title">Dostępna aktualiacja aplikacji</string>
+    <string name="update_available_format">Używasz starej wersji aplikacji Szkolny.eu (%s). Aby móc korzystać z aplikacji oraz zapewnić najlepsze działanie, zaktualizuj aplikację do wersji %s.\n\nDziennik zmian:\n%s</string>
+    <string name="update_available_fallback">Posiadasz nieaktualną wersję aplikacji Szkolny.eu. Aby móc dalej synchronizować dane, musisz zaktualizować aplikację.</string>
+    <string name="update_available_button">Aktualizuj</string>
+    <string name="update_available_later">Nie teraz</string>
+    <string name="home_availability_title">Dostępna aktualizacja</string>
+    <string name="home_availability_text">Zaktualizuj aplikację do najnowszej wersji %s.</string>
+    <string name="home_availability_info">Zobacz więcej</string>
+    <string name="home_availability_update">Aktualizuj</string>
+    <string name="register_unavailable_read_more">Dowiedz się więcej</string>
 </resources>
diff --git a/build.gradle b/build.gradle
index fb7bfd13..ddc5183a 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,8 +5,8 @@ buildscript {
         kotlin_version = '1.3.61'
 
         release = [
-                versionName: "4.3.1",
-                versionCode: 4030199
+                versionName: "4.4",
+                versionCode: 4040099
         ]
 
         setup = [