diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 250d604..86fe305 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -29,6 +29,7 @@
     </queries>
 
     <application
+        android:name=".MoneroApplication"
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
diff --git a/app/src/main/java/com/m2049r/xmrwallet/MainActivity.java b/app/src/main/java/com/m2049r/xmrwallet/MainActivity.java
index d8579c7..80ce9bc 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/MainActivity.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/MainActivity.java
@@ -1,9 +1,12 @@
 package com.m2049r.xmrwallet;
 
 import android.os.Bundle;
+import android.os.PersistableBundle;
 import android.widget.Toast;
 
+import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.app.AppCompatDelegate;
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 import androidx.navigation.fragment.NavHostFragment;
@@ -21,6 +24,7 @@ import com.m2049r.xmrwallet.service.MoneroHandlerThread;
 import com.m2049r.xmrwallet.service.PrefService;
 import com.m2049r.xmrwallet.service.TxService;
 import com.m2049r.xmrwallet.util.Constants;
+import com.m2049r.xmrwallet.util.DayNightMode;
 import com.m2049r.xmrwallet.util.NightmodeHelper;
 
 import java.io.File;
@@ -28,9 +32,7 @@ import java.io.File;
 public class MainActivity extends AppCompatActivity implements MoneroHandlerThread.Listener, PasswordBottomSheetDialog.PasswordListener {
     public final SingleLiveEvent restartEvents = new SingleLiveEvent();
     private MoneroHandlerThread thread = null;
-    private TxService txService = null;
     private BalanceService balanceService = null;
-    private AddressService addressService = null;
     private HistoryService historyService = null;
     private BlockchainService blockchainService = null;
 
@@ -38,13 +40,10 @@ public class MainActivity extends AppCompatActivity implements MoneroHandlerThre
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        NightmodeHelper.getAndSetPreferredNightmode(this);
         File walletFile = new File(getApplicationInfo().dataDir, Constants.WALLET_NAME);
-        new PrefService(this);
-
-        if(walletFile.exists()) {
+        if (walletFile.exists()) {
             boolean promptPassword = PrefService.getInstance().getBoolean(Constants.PREF_USES_PASSWORD, false);
-            if(!promptPassword) {
+            if (!promptPassword) {
                 init(walletFile, "");
             } else {
                 PasswordBottomSheetDialog passwordDialog = new PasswordBottomSheetDialog();
@@ -56,6 +55,11 @@ public class MainActivity extends AppCompatActivity implements MoneroHandlerThre
         }
     }
 
+    @Override
+    public void onPostCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
+        super.onPostCreate(savedInstanceState, persistentState);
+    }
+
     private void navigate(int destination) {
         FragmentActivity activity = this;
         FragmentManager fm = activity.getSupportFragmentManager();
@@ -73,11 +77,11 @@ public class MainActivity extends AppCompatActivity implements MoneroHandlerThre
     public void init(File walletFile, String password) {
         Wallet wallet = WalletManager.getInstance().openWallet(walletFile.getAbsolutePath(), password);
         thread = new MoneroHandlerThread("WalletService", this, wallet);
-        this.txService = new TxService(this, thread);
-        this.balanceService = new BalanceService(this, thread);
-        this.addressService = new AddressService(this, thread);
-        this.historyService = new HistoryService(this, thread);
-        this.blockchainService = new BlockchainService(this, thread);
+        new TxService(thread);
+        this.balanceService = new BalanceService(thread);
+        new AddressService(thread);
+        this.historyService = new HistoryService(thread);
+        this.blockchainService = new BlockchainService(thread);
         thread.start();
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/MoneroApplication.java b/app/src/main/java/com/m2049r/xmrwallet/MoneroApplication.java
new file mode 100644
index 0000000..59e1583
--- /dev/null
+++ b/app/src/main/java/com/m2049r/xmrwallet/MoneroApplication.java
@@ -0,0 +1,15 @@
+package com.m2049r.xmrwallet;
+
+import android.app.Application;
+
+import com.m2049r.xmrwallet.service.PrefService;
+import com.m2049r.xmrwallet.util.NightmodeHelper;
+
+public class MoneroApplication extends Application {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        new PrefService(this);
+        NightmodeHelper.getAndSetPreferredNightmode();
+    }
+}
diff --git a/app/src/main/java/com/m2049r/xmrwallet/fragment/settings/SettingsFragment.java b/app/src/main/java/com/m2049r/xmrwallet/fragment/settings/SettingsFragment.java
index 3bf5883..c9a47d3 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/fragment/settings/SettingsFragment.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/fragment/settings/SettingsFragment.java
@@ -54,12 +54,12 @@ public class SettingsFragment extends Fragment implements PasswordBottomSheetDia
         stringBuilder.append("Daemon height: " + BlockchainService.getInstance().getDaemonHeight() + "\n\n");
         walletInfoTextView.setText(stringBuilder.toString());
 
-        nightModeSwitch.setChecked(NightmodeHelper.getPreferredNightmode(getContext()) == DayNightMode.NIGHT);
+        nightModeSwitch.setChecked(NightmodeHelper.getPreferredNightmode() == DayNightMode.NIGHT);
         nightModeSwitch.setOnCheckedChangeListener((compoundButton, b) -> {
             if(b) {
-                NightmodeHelper.setAndSavePreferredNightmode(getContext(), DayNightMode.NIGHT);
+                NightmodeHelper.setAndSavePreferredNightmode(DayNightMode.NIGHT);
             } else {
-                NightmodeHelper.setAndSavePreferredNightmode(getContext(), DayNightMode.DAY);
+                NightmodeHelper.setAndSavePreferredNightmode(DayNightMode.DAY);
             }
         });
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/AddressService.java b/app/src/main/java/com/m2049r/xmrwallet/service/AddressService.java
index c28a608..70f2f99 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/AddressService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/AddressService.java
@@ -13,8 +13,8 @@ public class AddressService extends ServiceBase {
         return instance;
     }
 
-    public AddressService(MainActivity mainActivity, MoneroHandlerThread thread) {
-        super(mainActivity, thread);
+    public AddressService(MoneroHandlerThread thread) {
+        super(thread);
         instance = this;
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/BalanceService.java b/app/src/main/java/com/m2049r/xmrwallet/service/BalanceService.java
index 1ac45da..ff68ea4 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/BalanceService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/BalanceService.java
@@ -18,8 +18,8 @@ public class BalanceService extends ServiceBase {
     private final MutableLiveData<Long> _lockedBalance = new MutableLiveData<>(0L);
     public LiveData<Long> lockedBalance = _lockedBalance;
 
-    public BalanceService(MainActivity mainActivity, MoneroHandlerThread thread) {
-        super(mainActivity, thread);
+    public BalanceService(MoneroHandlerThread thread) {
+        super(thread);
         instance = this;
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/BlockchainService.java b/app/src/main/java/com/m2049r/xmrwallet/service/BlockchainService.java
index 3892038..a2fb312 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/BlockchainService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/BlockchainService.java
@@ -18,8 +18,8 @@ public class BlockchainService extends ServiceBase {
     private final MutableLiveData<Long> _currentHeight = new MutableLiveData<>(0L);
     public LiveData<Long> height = _currentHeight;
 
-    public BlockchainService(MainActivity mainActivity, MoneroHandlerThread thread) {
-        super(mainActivity, thread);
+    public BlockchainService(MoneroHandlerThread thread) {
+        super(thread);
         instance = this;
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/HistoryService.java b/app/src/main/java/com/m2049r/xmrwallet/service/HistoryService.java
index 7efb8cb..aee07eb 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/HistoryService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/HistoryService.java
@@ -20,8 +20,8 @@ public class HistoryService extends ServiceBase {
     private final MutableLiveData<List<TransactionInfo>> _history = new MutableLiveData<>();
     public LiveData<List<TransactionInfo>> history = _history;
 
-    public HistoryService(MainActivity mainActivity, MoneroHandlerThread thread) {
-        super(mainActivity, thread);
+    public HistoryService(MoneroHandlerThread thread) {
+        super(thread);
         instance = this;
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/PrefService.java b/app/src/main/java/com/m2049r/xmrwallet/service/PrefService.java
index e54d9fd..10495c6 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/PrefService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/PrefService.java
@@ -4,6 +4,7 @@ import android.content.Context;
 import android.content.SharedPreferences;
 
 import com.m2049r.xmrwallet.MainActivity;
+import com.m2049r.xmrwallet.MoneroApplication;
 
 public class PrefService extends ServiceBase {
     public static SharedPreferences instance = null;
@@ -12,8 +13,8 @@ public class PrefService extends ServiceBase {
         return instance;
     }
 
-    public PrefService(MainActivity mainActivity) {
-        super(mainActivity, null);
-        instance = mainActivity.getSharedPreferences(mainActivity.getApplicationInfo().packageName, Context.MODE_PRIVATE);
+    public PrefService(MoneroApplication application) {
+        super(null);
+        instance = application.getSharedPreferences(application.getApplicationInfo().packageName, Context.MODE_PRIVATE);
     }
 }
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/ServiceBase.java b/app/src/main/java/com/m2049r/xmrwallet/service/ServiceBase.java
index 28b2a95..14adbfb 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/ServiceBase.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/ServiceBase.java
@@ -1,20 +1,12 @@
 package com.m2049r.xmrwallet.service;
 
-import com.m2049r.xmrwallet.MainActivity;
-
 public class ServiceBase {
-    private final MainActivity mainActivity;
     private final MoneroHandlerThread thread;
 
-    public ServiceBase(MainActivity mainActivity, MoneroHandlerThread thread) {
-        this.mainActivity = mainActivity;
+    public ServiceBase(MoneroHandlerThread thread) {
         this.thread = thread;
     }
 
-    public MainActivity getMainActivity() {
-        return mainActivity;
-    }
-
     public MoneroHandlerThread getThread() {
         return thread;
     }
diff --git a/app/src/main/java/com/m2049r/xmrwallet/service/TxService.java b/app/src/main/java/com/m2049r/xmrwallet/service/TxService.java
index 8a2dd95..76c70ba 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/service/TxService.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/service/TxService.java
@@ -10,8 +10,8 @@ public class TxService extends ServiceBase {
         return instance;
     }
 
-    public TxService(MainActivity mainActivity, MoneroHandlerThread thread) {
-        super(mainActivity, thread);
+    public TxService(MoneroHandlerThread thread) {
+        super(thread);
         instance = this;
     }
 
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/Constants.java b/app/src/main/java/com/m2049r/xmrwallet/util/Constants.java
index c819cb5..496356a 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/Constants.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/Constants.java
@@ -5,4 +5,5 @@ public class Constants {
     public static final String MNEMONIC_LANGUAGE = "English";
     public static final String PREF_USES_PASSWORD = "pref_uses_password";
     public static final String PREF_USES_TOR = "pref_uses_tor";
+    public static final String PREF_NIGHT_MODE = "pref_night_mode";
 }
diff --git a/app/src/main/java/com/m2049r/xmrwallet/util/NightmodeHelper.java b/app/src/main/java/com/m2049r/xmrwallet/util/NightmodeHelper.java
index d3094b8..120c389 100644
--- a/app/src/main/java/com/m2049r/xmrwallet/util/NightmodeHelper.java
+++ b/app/src/main/java/com/m2049r/xmrwallet/util/NightmodeHelper.java
@@ -23,30 +23,19 @@ import android.preference.PreferenceManager;
 import androidx.appcompat.app.AppCompatDelegate;
 
 import com.m2049r.xmrwallet.R;
+import com.m2049r.xmrwallet.service.PrefService;
 
 public class NightmodeHelper {
-    public static DayNightMode getPreferredNightmode(Context context) {
-        DayNightMode mode = DayNightMode.valueOf(PreferenceManager.getDefaultSharedPreferences(context)
-                .getString(context.getString(R.string.preferred_nightmode), "UNKNOWN"));
-        if(mode == DayNightMode.UNKNOWN) {
-            mode = DayNightMode.NIGHT;
-        }
-        return mode;
+    public static DayNightMode getPreferredNightmode() {
+        return DayNightMode.valueOf(PrefService.getInstance().getString(Constants.PREF_NIGHT_MODE, DayNightMode.NIGHT.name()));
     }
 
-    public static void getAndSetPreferredNightmode(Context context) {
-        DayNightMode mode = DayNightMode.valueOf(PreferenceManager.getDefaultSharedPreferences(context)
-                .getString(context.getString(R.string.preferred_nightmode), "UNKNOWN"));
-        if(mode == DayNightMode.UNKNOWN) {
-            mode = DayNightMode.NIGHT;
-        }
-
-        setNightMode(mode);
+    public static void getAndSetPreferredNightmode() {
+        setNightMode(getPreferredNightmode());
     }
 
-    public static void setAndSavePreferredNightmode(Context context, DayNightMode mode) {
-        PreferenceManager.getDefaultSharedPreferences(context).edit()
-                .putString(context.getString(R.string.preferred_nightmode), mode.name()).apply();
+    public static void setAndSavePreferredNightmode(DayNightMode mode) {
+        PrefService.getInstance().edit().putString(Constants.PREF_NIGHT_MODE, mode.name()).apply();
         setNightMode(mode);
     }