diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index f97947c..a868652 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -48,7 +48,7 @@
         </activity>
         <activity
             android:name=".ComposeMessageActivity"
-            android:label="Compose"
+            android:label="@string/compose_message"
             android:parentActivityName=".MainActivity">
             <meta-data
                 android:name="android.support.PARENT_ACTIVITY"
diff --git a/app/src/main/java/ch/dissem/apps/abit/notification/ProofOfWorkNotification.java b/app/src/main/java/ch/dissem/apps/abit/notification/ProofOfWorkNotification.java
index 408bc5d..73657e2 100644
--- a/app/src/main/java/ch/dissem/apps/abit/notification/ProofOfWorkNotification.java
+++ b/app/src/main/java/ch/dissem/apps/abit/notification/ProofOfWorkNotification.java
@@ -32,7 +32,7 @@ public class ProofOfWorkNotification extends AbstractNotification {
 
     public ProofOfWorkNotification(Context ctx) {
         super(ctx);
-        update(1);
+        update(0);
     }
 
     @Override
@@ -52,7 +52,9 @@ public class ProofOfWorkNotification extends AbstractNotification {
                 .setOngoing(true)
                 .setSmallIcon(R.drawable.ic_notification_proof_of_work)
                 .setContentTitle(ctx.getString(R.string.proof_of_work_title))
-                .setContentText(ctx.getString(R.string.proof_of_work_text, numberOfItems))
+                .setContentText(numberOfItems == 0
+                        ? ctx.getString(R.string.proof_of_work_text_0)
+                        : ctx.getString(R.string.proof_of_work_text_n, numberOfItems))
                 .setContentIntent(pendingIntent);
 
         notification = builder.build();
diff --git a/app/src/main/java/ch/dissem/apps/abit/service/ProofOfWorkService.java b/app/src/main/java/ch/dissem/apps/abit/service/ProofOfWorkService.java
index 7eee67d..cb61cf3 100644
--- a/app/src/main/java/ch/dissem/apps/abit/service/ProofOfWorkService.java
+++ b/app/src/main/java/ch/dissem/apps/abit/service/ProofOfWorkService.java
@@ -37,19 +37,13 @@ import static ch.dissem.apps.abit.notification.ProofOfWorkNotification.ONGOING_N
  */
 public class ProofOfWorkService extends Service {
     // Object to use as a thread-safe lock
-    private static final Object lock = new Object();
-    private static ProofOfWorkEngine engine;
+    private static ProofOfWorkEngine engine = new MultiThreadedPOWEngine();
     private static boolean calculating;
     private static final Queue<PowItem> queue = new LinkedList<>();
     private static ProofOfWorkNotification notification;
 
     @Override
     public void onCreate() {
-        synchronized (lock) {
-            if (engine == null) {
-                engine = new MultiThreadedPOWEngine();
-            }
-        }
         notification = new ProofOfWorkNotification(this);
     }
 
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index 76473aa..95d73b8 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -42,7 +42,8 @@
     <string name="connection_info_n">Stream %1$d: %2$d Verbindungen</string>
     <string name="connection_info_disconnected">Getrennt</string>
     <string name="connection_info_pending">Verbindung wird aufgebaut…</string>
-    <string name="proof_of_work_text">Arbeite am Versenden (%1$d in Warteschlange)</string>
+    <string name="proof_of_work_text_0">Arbeite am Versenden</string>
+    <string name="proof_of_work_text_n">Arbeite am Versenden (%1$d in Warteschlange)</string>
     <string name="proof_of_work_title">Proof of Work</string>
     <string name="error_invalid_sync_host">Synchronisation fehlgeschlagen: der vertrauenswürdige Knoten konnte nicht erreicht werden.</string>
     <string name="error_invalid_sync_port">Ungültiger Port in den Synchronisationseinstellungen: %s</string>
@@ -73,4 +74,5 @@ Als Alternative kann in den Einstellungen ein vertrauenswürdiger Knoten konfigu
     <string name="error_illegal_address">Vielleicht hat es einen Tippfehler</string>
     <string name="export">Exportieren</string>
     <string name="confirm_export">Identität wirklich exportieren? Der Export wird die privaten Schlüssel unverschlüsselt enthalten.</string>
+    <string name="compose_message">Schreiben</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 9bd6afc..49e4b52 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -44,7 +44,8 @@
     <string name="connection_info_disconnected">Disconnected</string>
     <string name="connection_info_pending">Connecting…</string>
     <string name="proof_of_work_title">Proof of Work</string>
-    <string name="proof_of_work_text">Doing work to send message (%1$d queued)</string>
+    <string name="proof_of_work_text_0">Doing work to send message</string>
+    <string name="proof_of_work_text_n">Doing work to send message (%1$d queued)</string>
     <string name="error_invalid_sync_port">Invalid port in synchronization settings: %s</string>
     <string name="error_invalid_sync_host">Synchronization failed: Trusted node could not be reached.</string>
     <string name="compose_body_hint">Write message</string>
@@ -76,4 +77,5 @@ As an alternative you could configure a trusted node in the settings, but as of
     <string name="error_illegal_address">There might be a typo</string>
     <string name="export">Export</string>
     <string name="confirm_export">Do you really want to export your identity? The export will contain the unencrypted private keys.</string>
+    <string name="compose_message">Compose</string>
 </resources>