diff --git a/app/src/main/java/com/github/gotify/MarkwonFactory.kt b/app/src/main/java/com/github/gotify/MarkwonFactory.kt
index 3692d91..69b8ee6 100644
--- a/app/src/main/java/com/github/gotify/MarkwonFactory.kt
+++ b/app/src/main/java/com/github/gotify/MarkwonFactory.kt
@@ -20,7 +20,7 @@ import org.commonmark.ext.gfm.tables.TablesExtension
 import org.commonmark.node.*
 import org.commonmark.parser.Parser
 
-object MarkwonFactory {
+internal object MarkwonFactory {
     fun createForMessage(context: Context, picasso: Picasso): Markwon {
         return Markwon.builder(context)
             .usePlugin(CorePlugin.create())
diff --git a/app/src/main/java/com/github/gotify/MissedMessageUtil.kt b/app/src/main/java/com/github/gotify/MissedMessageUtil.kt
index aa598f5..92c2fd8 100644
--- a/app/src/main/java/com/github/gotify/MissedMessageUtil.kt
+++ b/app/src/main/java/com/github/gotify/MissedMessageUtil.kt
@@ -9,7 +9,7 @@ import com.github.gotify.client.model.Message
 import com.github.gotify.client.model.PagedMessages
 import com.github.gotify.log.Log
 
-class MissedMessageUtil(private val api: MessageApi) {
+internal class MissedMessageUtil(private val api: MessageApi) {
     fun lastReceivedMessage(successCallback: SuccessCallback<Long?>) {
         api.getMessages(1, 0L).enqueue(
             Callback.call({ messages: PagedMessages? ->
diff --git a/app/src/main/java/com/github/gotify/NotificationSupport.kt b/app/src/main/java/com/github/gotify/NotificationSupport.kt
index 548cc2f..46a5287 100644
--- a/app/src/main/java/com/github/gotify/NotificationSupport.kt
+++ b/app/src/main/java/com/github/gotify/NotificationSupport.kt
@@ -7,7 +7,7 @@ import android.os.Build
 import androidx.annotation.RequiresApi
 import com.github.gotify.log.Log
 
-object NotificationSupport {
+internal object NotificationSupport {
     @RequiresApi(Build.VERSION_CODES.O)
     fun createChannels(notificationManager: NotificationManager) {
         try {
diff --git a/app/src/main/java/com/github/gotify/SSLSettings.kt b/app/src/main/java/com/github/gotify/SSLSettings.kt
index 297bcf1..70ce9fc 100644
--- a/app/src/main/java/com/github/gotify/SSLSettings.kt
+++ b/app/src/main/java/com/github/gotify/SSLSettings.kt
@@ -1,3 +1,3 @@
 package com.github.gotify
 
-class SSLSettings(val validateSSL: Boolean, val cert: String)
+internal class SSLSettings(val validateSSL: Boolean, val cert: String)
diff --git a/app/src/main/java/com/github/gotify/Settings.kt b/app/src/main/java/com/github/gotify/Settings.kt
index e68d48e..6368c63 100644
--- a/app/src/main/java/com/github/gotify/Settings.kt
+++ b/app/src/main/java/com/github/gotify/Settings.kt
@@ -4,7 +4,7 @@ import android.content.Context
 import android.content.SharedPreferences
 import com.github.gotify.client.model.User
 
-class Settings(context: Context) {
+internal class Settings(context: Context) {
     private val sharedPreferences: SharedPreferences
     var url: String
         get() = sharedPreferences.getString("url", "")!!
diff --git a/app/src/main/java/com/github/gotify/Utils.kt b/app/src/main/java/com/github/gotify/Utils.kt
index a6e9e10..9643cab 100644
--- a/app/src/main/java/com/github/gotify/Utils.kt
+++ b/app/src/main/java/com/github/gotify/Utils.kt
@@ -24,7 +24,7 @@ import java.net.URI
 import java.net.URISyntaxException
 import java.net.URL
 
-object Utils {
+internal object Utils {
     val JSON: Gson = JSON().gson
 
     fun showSnackBar(activity: Activity, message: String?) {
diff --git a/app/src/main/java/com/github/gotify/api/Api.kt b/app/src/main/java/com/github/gotify/api/Api.kt
index af05190..5874e95 100644
--- a/app/src/main/java/com/github/gotify/api/Api.kt
+++ b/app/src/main/java/com/github/gotify/api/Api.kt
@@ -3,7 +3,7 @@ package com.github.gotify.api
 import java.io.IOException
 import retrofit2.Call
 
-object Api {
+internal object Api {
     @Throws(ApiException::class)
     fun <T> execute(call: Call<T>): T? {
         try {
diff --git a/app/src/main/java/com/github/gotify/init/BootCompletedReceiver.kt b/app/src/main/java/com/github/gotify/init/BootCompletedReceiver.kt
index 29f0c4b..c055c4e 100644
--- a/app/src/main/java/com/github/gotify/init/BootCompletedReceiver.kt
+++ b/app/src/main/java/com/github/gotify/init/BootCompletedReceiver.kt
@@ -7,7 +7,7 @@ import android.os.Build
 import com.github.gotify.Settings
 import com.github.gotify.service.WebSocketService
 
-class BootCompletedReceiver : BroadcastReceiver() {
+internal class BootCompletedReceiver : BroadcastReceiver() {
 
     override fun onReceive(context: Context, intent: Intent) {
         val settings = Settings(context)
diff --git a/app/src/main/java/com/github/gotify/init/InitializationActivity.kt b/app/src/main/java/com/github/gotify/init/InitializationActivity.kt
index 675ba55..8ecbaeb 100644
--- a/app/src/main/java/com/github/gotify/init/InitializationActivity.kt
+++ b/app/src/main/java/com/github/gotify/init/InitializationActivity.kt
@@ -23,7 +23,7 @@ import com.github.gotify.messages.MessagesActivity
 import com.github.gotify.service.WebSocketService
 import com.github.gotify.settings.ThemeHelper
 
-class InitializationActivity : AppCompatActivity() {
+internal class InitializationActivity : AppCompatActivity() {
 
     private lateinit var settings: Settings
 
diff --git a/app/src/main/java/com/github/gotify/login/LoginActivity.kt b/app/src/main/java/com/github/gotify/login/LoginActivity.kt
index 4c81dc1..57aa47b 100644
--- a/app/src/main/java/com/github/gotify/login/LoginActivity.kt
+++ b/app/src/main/java/com/github/gotify/login/LoginActivity.kt
@@ -34,7 +34,7 @@ import com.github.gotify.log.UncaughtExceptionHandler
 import java.security.cert.X509Certificate
 import okhttp3.HttpUrl
 
-class LoginActivity : AppCompatActivity() {
+internal class LoginActivity : AppCompatActivity() {
     companion object {
         // return value from startActivityForResult when choosing a certificate
         private const val FILE_SELECT_CODE = 1
@@ -82,7 +82,7 @@ class LoginActivity : AppCompatActivity() {
         binding.checkurl.text = getString(R.string.check_url)
     }
 
-    fun doCheckUrl() {
+    private fun doCheckUrl() {
         val url = binding.gotifyUrl.text.toString()
         val parsedUrl = HttpUrl.parse(url)
         if (parsedUrl == null) {
@@ -114,7 +114,7 @@ class LoginActivity : AppCompatActivity() {
         }
     }
 
-    fun showHttpWarning() {
+    private fun showHttpWarning() {
         AlertDialog.Builder(ContextThemeWrapper(this, R.style.AppTheme_Dialog))
             .setTitle(R.string.warning)
             .setCancelable(true)
@@ -123,11 +123,11 @@ class LoginActivity : AppCompatActivity() {
             .show()
     }
 
-    fun openLogs() {
+    private fun openLogs() {
         startActivity(Intent(this, LogsActivity::class.java))
     }
 
-    fun toggleShowAdvanced() {
+    private fun toggleShowAdvanced() {
         val selectedCertName = if (caCertContents != null) {
             getNameOfCertContent(caCertContents!!)
         } else null
@@ -215,7 +215,7 @@ class LoginActivity : AppCompatActivity() {
         }
     }
 
-    fun doLogin() {
+    private fun doLogin() {
         val username = binding.username.text.toString()
         val password = binding.password.text.toString()
 
@@ -251,7 +251,10 @@ class LoginActivity : AppCompatActivity() {
             .show()
     }
 
-    fun doCreateClient(client: ApiClient, nameProvider: EditText): DialogInterface.OnClickListener {
+    private fun doCreateClient(
+        client: ApiClient,
+        nameProvider: EditText
+    ): DialogInterface.OnClickListener {
         return DialogInterface.OnClickListener { _, _ ->
             val newClient = Client().name(nameProvider.text.toString())
             client.createService(ClientApi::class.java)
diff --git a/app/src/main/java/com/github/gotify/messages/Extras.kt b/app/src/main/java/com/github/gotify/messages/Extras.kt
index 41b98c1..db43db1 100644
--- a/app/src/main/java/com/github/gotify/messages/Extras.kt
+++ b/app/src/main/java/com/github/gotify/messages/Extras.kt
@@ -2,7 +2,7 @@ package com.github.gotify.messages
 
 import com.github.gotify.client.model.Message
 
-object Extras {
+internal object Extras {
     fun useMarkdown(message: Message): Boolean {
         return useMarkdown(message.extras)
     }
diff --git a/app/src/main/java/com/github/gotify/messages/ListMessageAdapter.kt b/app/src/main/java/com/github/gotify/messages/ListMessageAdapter.kt
index 64e68f3..0c525e5 100644
--- a/app/src/main/java/com/github/gotify/messages/ListMessageAdapter.kt
+++ b/app/src/main/java/com/github/gotify/messages/ListMessageAdapter.kt
@@ -30,7 +30,7 @@ import org.threeten.bp.OffsetDateTime
 import java.text.DateFormat
 import java.util.*
 
-class ListMessageAdapter(
+internal class ListMessageAdapter(
     private val context: Context,
     private val settings: Settings,
     private val picasso: Picasso,
diff --git a/app/src/main/java/com/github/gotify/messages/MessagesActivity.kt b/app/src/main/java/com/github/gotify/messages/MessagesActivity.kt
index 34bd7e7..2c3df95 100644
--- a/app/src/main/java/com/github/gotify/messages/MessagesActivity.kt
+++ b/app/src/main/java/com/github/gotify/messages/MessagesActivity.kt
@@ -57,7 +57,10 @@ import com.google.android.material.snackbar.BaseTransientBottomBar.BaseCallback
 import com.google.android.material.snackbar.Snackbar
 import java.io.IOException
 
-class MessagesActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelectedListener {
+internal class MessagesActivity :
+    AppCompatActivity(),
+    NavigationView.OnNavigationItemSelectedListener
+{
     private lateinit var binding: ActivityMessagesBinding
     private lateinit var viewModel: MessagesModel
     private var isLoadMore = false
@@ -148,11 +151,11 @@ class MessagesActivity : AppCompatActivity(), NavigationView.OnNavigationItemSel
         binding.learnGotify.setOnClickListener { openDocumentation() }
     }
 
-    fun onRefreshAll(view: View?) {
+    private fun onRefreshAll(view: View?) {
         refreshAll()
     }
 
-    fun refreshAll() {
+    private fun refreshAll() {
         try {
             viewModel.picassoHandler.evict()
         } catch (e: IOException) {
@@ -176,7 +179,7 @@ class MessagesActivity : AppCompatActivity(), NavigationView.OnNavigationItemSel
         CommitDeleteMessage().execute()
     }
 
-    protected fun onUpdateApps(applications: List<Application>) {
+    private fun onUpdateApps(applications: List<Application>) {
         val menu: Menu = binding.navView.menu
         menu.removeGroup(R.id.apps)
         viewModel.targetReferences.clear()
@@ -278,7 +281,7 @@ class MessagesActivity : AppCompatActivity(), NavigationView.OnNavigationItemSel
         return true
     }
 
-    fun doLogout() {
+    private fun doLogout() {
         setContentView(R.layout.splash)
         DeleteClientAndNavigateToLogin().execute()
     }
diff --git a/app/src/main/java/com/github/gotify/messages/MessagesModel.kt b/app/src/main/java/com/github/gotify/messages/MessagesModel.kt
index 10c5f54..3565a39 100644
--- a/app/src/main/java/com/github/gotify/messages/MessagesModel.kt
+++ b/app/src/main/java/com/github/gotify/messages/MessagesModel.kt
@@ -12,7 +12,7 @@ import com.github.gotify.messages.provider.MessageState
 import com.github.gotify.picasso.PicassoHandler
 import com.squareup.picasso.Target
 
-class MessagesModel(parentView: Activity) : ViewModel() {
+internal class MessagesModel(parentView: Activity) : ViewModel() {
     val settings: Settings
     val picassoHandler: PicassoHandler
     val client: ApiClient
diff --git a/app/src/main/java/com/github/gotify/messages/MessagesModelFactory.kt b/app/src/main/java/com/github/gotify/messages/MessagesModelFactory.kt
index 443c987..32d8def 100644
--- a/app/src/main/java/com/github/gotify/messages/MessagesModelFactory.kt
+++ b/app/src/main/java/com/github/gotify/messages/MessagesModelFactory.kt
@@ -4,7 +4,9 @@ import android.app.Activity
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 
-class MessagesModelFactory(var modelParameterActivity: Activity) : ViewModelProvider.Factory {
+internal class MessagesModelFactory(
+    var modelParameterActivity: Activity
+) : ViewModelProvider.Factory {
     override fun <T : ViewModel> create(modelClass: Class<T>): T {
         if (modelClass == MessagesModel::class.java) {
             return modelClass.cast(MessagesModel(modelParameterActivity)) as T
diff --git a/app/src/main/java/com/github/gotify/messages/provider/ApplicationHolder.kt b/app/src/main/java/com/github/gotify/messages/provider/ApplicationHolder.kt
index a27e4c7..4af9a25 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/ApplicationHolder.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/ApplicationHolder.kt
@@ -8,7 +8,7 @@ import com.github.gotify.client.ApiClient
 import com.github.gotify.client.api.ApplicationApi
 import com.github.gotify.client.model.Application
 
-class ApplicationHolder(private val activity: Activity, private val client: ApiClient) {
+internal class ApplicationHolder(private val activity: Activity, private val client: ApiClient) {
     private var state: List<Application> = listOf()
     private var onUpdate: Runnable? = null
     private var onUpdateFailed: Runnable? = null
diff --git a/app/src/main/java/com/github/gotify/messages/provider/MessageDeletion.kt b/app/src/main/java/com/github/gotify/messages/provider/MessageDeletion.kt
index f357b42..14cc1e4 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/MessageDeletion.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/MessageDeletion.kt
@@ -2,7 +2,7 @@ package com.github.gotify.messages.provider
 
 import com.github.gotify.client.model.Message
 
-class MessageDeletion(
+internal class MessageDeletion(
     val message: Message,
     val allPosition: Int,
     val appPosition: Int
diff --git a/app/src/main/java/com/github/gotify/messages/provider/MessageFacade.kt b/app/src/main/java/com/github/gotify/messages/provider/MessageFacade.kt
index f0b338c..c023ded 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/MessageFacade.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/MessageFacade.kt
@@ -3,7 +3,7 @@ package com.github.gotify.messages.provider
 import com.github.gotify.client.api.MessageApi
 import com.github.gotify.client.model.Message
 
-class MessageFacade(api: MessageApi, private val applicationHolder: ApplicationHolder) {
+internal class MessageFacade(api: MessageApi, private val applicationHolder: ApplicationHolder) {
     private val requester: MessageRequester
     private val state: MessageStateHolder
 
diff --git a/app/src/main/java/com/github/gotify/messages/provider/MessageImageCombiner.kt b/app/src/main/java/com/github/gotify/messages/provider/MessageImageCombiner.kt
index 90953e9..7095aec 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/MessageImageCombiner.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/MessageImageCombiner.kt
@@ -3,7 +3,7 @@ package com.github.gotify.messages.provider
 import com.github.gotify.client.model.Application
 import com.github.gotify.client.model.Message
 
-object MessageImageCombiner {
+internal object MessageImageCombiner {
     fun combine(messages: List<Message>, applications: List<Application>): List<MessageWithImage> {
         val appIdToImage = appIdToImage(applications)
         val result = mutableListOf<MessageWithImage>()
diff --git a/app/src/main/java/com/github/gotify/messages/provider/MessageState.kt b/app/src/main/java/com/github/gotify/messages/provider/MessageState.kt
index 1694080..3b0bda0 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/MessageState.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/MessageState.kt
@@ -2,7 +2,7 @@ package com.github.gotify.messages.provider
 
 import com.github.gotify.client.model.Message
 
-class MessageState {
+internal class MessageState {
     var appId = 0L
     var loaded = false
     var hasNext = false
diff --git a/app/src/main/java/com/github/gotify/messages/provider/MessageWithImage.kt b/app/src/main/java/com/github/gotify/messages/provider/MessageWithImage.kt
index 9690e06..e99f730 100644
--- a/app/src/main/java/com/github/gotify/messages/provider/MessageWithImage.kt
+++ b/app/src/main/java/com/github/gotify/messages/provider/MessageWithImage.kt
@@ -2,7 +2,7 @@ package com.github.gotify.messages.provider
 
 import com.github.gotify.client.model.Message
 
-class MessageWithImage {
+internal class MessageWithImage {
     lateinit var message: Message
     lateinit var image: String
 }
diff --git a/app/src/main/java/com/github/gotify/picasso/PicassoDataRequestHandler.kt b/app/src/main/java/com/github/gotify/picasso/PicassoDataRequestHandler.kt
index 9056a7b..d3e2d3f 100644
--- a/app/src/main/java/com/github/gotify/picasso/PicassoDataRequestHandler.kt
+++ b/app/src/main/java/com/github/gotify/picasso/PicassoDataRequestHandler.kt
@@ -11,8 +11,7 @@ import com.squareup.picasso.RequestHandler
  * Adapted from https://github.com/square/picasso/issues/1395#issuecomment-220929377 By
  * https://github.com/SmartDengg
  */
-class PicassoDataRequestHandler : RequestHandler() {
-
+internal class PicassoDataRequestHandler : RequestHandler() {
     companion object {
         private const val DATA_SCHEME = "data"
     }
diff --git a/app/src/main/java/com/github/gotify/picasso/PicassoHandler.kt b/app/src/main/java/com/github/gotify/picasso/PicassoHandler.kt
index ad780bf..7d2153c 100644
--- a/app/src/main/java/com/github/gotify/picasso/PicassoHandler.kt
+++ b/app/src/main/java/com/github/gotify/picasso/PicassoHandler.kt
@@ -19,8 +19,7 @@ import okhttp3.OkHttpClient
 import java.io.File
 import java.io.IOException
 
-class PicassoHandler(private val context: Context, private val settings: Settings) {
-
+internal class PicassoHandler(private val context: Context, private val settings: Settings) {
     companion object {
         private const val PICASSO_CACHE_SIZE = 50 * 1024 * 1024 // 50 MB
         private const val PICASSO_CACHE_SUBFOLDER = "picasso-cache"
diff --git a/app/src/main/java/com/github/gotify/service/WebSocketService.kt b/app/src/main/java/com/github/gotify/service/WebSocketService.kt
index ba3718e..3068a31 100644
--- a/app/src/main/java/com/github/gotify/service/WebSocketService.kt
+++ b/app/src/main/java/com/github/gotify/service/WebSocketService.kt
@@ -26,7 +26,7 @@ import com.github.gotify.service.WebSocketConnection.OnNetworkFailureRunnable
 import io.noties.markwon.Markwon
 import java.util.concurrent.atomic.AtomicLong
 
-class WebSocketService : Service() {
+internal class WebSocketService : Service() {
     companion object {
         val NEW_MESSAGE_BROADCAST = "${WebSocketService::class.java.name}.NEW_MESSAGE"
         private const val NOT_LOADED = -2L
diff --git a/app/src/main/java/com/github/gotify/settings/SettingsActivity.kt b/app/src/main/java/com/github/gotify/settings/SettingsActivity.kt
index 2a6f1a3..b6320b6 100644
--- a/app/src/main/java/com/github/gotify/settings/SettingsActivity.kt
+++ b/app/src/main/java/com/github/gotify/settings/SettingsActivity.kt
@@ -15,7 +15,7 @@ import androidx.preference.PreferenceManager
 import com.github.gotify.R
 import com.github.gotify.databinding.SettingsActivityBinding
 
-class SettingsActivity : AppCompatActivity(), OnSharedPreferenceChangeListener {
+internal class SettingsActivity : AppCompatActivity(), OnSharedPreferenceChangeListener {
     private lateinit var binding: SettingsActivityBinding
 
     override fun onCreate(savedInstanceState: Bundle?) {
diff --git a/app/src/main/java/com/github/gotify/settings/ThemeHelper.kt b/app/src/main/java/com/github/gotify/settings/ThemeHelper.kt
index e18c422..6557e61 100644
--- a/app/src/main/java/com/github/gotify/settings/ThemeHelper.kt
+++ b/app/src/main/java/com/github/gotify/settings/ThemeHelper.kt
@@ -5,7 +5,7 @@ import android.os.Build
 import androidx.appcompat.app.AppCompatDelegate
 import com.github.gotify.R
 
-object ThemeHelper {
+internal object ThemeHelper {
     fun setTheme(context: Context, newTheme: String) {
         AppCompatDelegate.setDefaultNightMode(ofKey(context, newTheme))
     }
diff --git a/app/src/main/java/com/github/gotify/sharing/ShareActivity.kt b/app/src/main/java/com/github/gotify/sharing/ShareActivity.kt
index 28773bc..4ffc365 100644
--- a/app/src/main/java/com/github/gotify/sharing/ShareActivity.kt
+++ b/app/src/main/java/com/github/gotify/sharing/ShareActivity.kt
@@ -22,7 +22,7 @@ import com.github.gotify.databinding.ActivityShareBinding
 import com.github.gotify.log.Log
 import com.github.gotify.messages.provider.ApplicationHolder
 
-class ShareActivity : AppCompatActivity() {
+internal class ShareActivity : AppCompatActivity() {
     private lateinit var binding: ActivityShareBinding
     private lateinit var settings: Settings
     private lateinit var appsHolder: ApplicationHolder
@@ -88,7 +88,7 @@ class ShareActivity : AppCompatActivity() {
         return false
     }
 
-    fun pushMessage() {
+    private fun pushMessage() {
         val titleText = binding.title.text.toString()
         val contentText = binding.content.text.toString()
         val priority = binding.edtTxtPriority.text.toString()