diff --git a/android/AndroidManifest.xml b/android/AndroidManifest.xml
index 0cfb299..8fba935 100644
--- a/android/AndroidManifest.xml
+++ b/android/AndroidManifest.xml
@@ -29,6 +29,7 @@
     <uses-permission android:name="android.permission.GET_ACCOUNTS" />
     <uses-permission android:name="android.permission.USE_CREDENTIALS" />
 
+    <!--
     <uses-permission
         android:name="android.permission.WRITE_EXTERNAL_STORAGE"
         android:maxSdkVersion="18" />
@@ -36,7 +37,7 @@
     <uses-permission
         android:name="android.permission.READ_EXTERNAL_STORAGE"
         android:maxSdkVersion="18" />
-
+    -->
     <application
         android:icon="@drawable/app_icon"
         android:label="@string/app_name"
@@ -71,7 +72,7 @@
         </activity>
 
         <!-- Handles incoming messages, using GCM 3.0 API -->
-        <service android:name=".GCMIntentService" >
+        <service android:name=".GCMIntentService" android:exported="false">
             <intent-filter>
                 <action android:name="com.google.android.c2dm.intent.RECEIVE" />
             </intent-filter>
diff --git a/android/build.gradle b/android/build.gradle
index 6cefede..96c07bd 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -15,10 +15,9 @@ dependencies {
     //compile project(path: ':backend', configuration: 'android-endpoints')
     compile 'com.android.support:support-v4:22.2.0'
     compile 'com.google.android.gms:play-services:7.5.0'
-        testCompile 'junit:junit:4.12'
-        testCompile "org.mockito:mockito-core:1.9.5"
+    testCompile 'junit:junit:4.12'
+    testCompile 'org.mockito:mockito-core:1.9.5'
     //testCompile ""
-
 }
 
 //http://tools.android.com/tech-docs/new-build-system/user-guide
@@ -50,7 +49,7 @@ android {
 
         }
 
-            // Move the build types to build-types/<type>
+        // Move the build types to build-types/<type>
         // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
         // This moves them out of them default location under src/<type>/... which would
         // conflict with src/ being used by the main source set.
@@ -69,7 +68,10 @@ android {
             // instance.
             // You can define a different keystore, and configure it against
             // a different base URL.
-            storeFile file("dev.keystore")
+            storeFile file('debug.keystore')
         }
     }
+    dexOptions {
+        incremental true
+    }
 }
diff --git a/android/src/com/google/android/apps/chrometophone/Prefs.java b/android/src/com/google/android/apps/chrometophone/Prefs.java
index 02b30d4..5eb0e3d 100644
--- a/android/src/com/google/android/apps/chrometophone/Prefs.java
+++ b/android/src/com/google/android/apps/chrometophone/Prefs.java
@@ -68,8 +68,20 @@ public final class Prefs {
 
     public static final String IID = "iid";
 
+    /** Certificate used to signed the release. Configured on the chrometophone
+     *  dev console.
+     */
     public static final String PROD_CERT = "24bb24c05e47e0aefa68a58a766179d9b613a600";
+
+    /**
+     * Certificate matching the debug.keystore checked into the build.
+     * This can't be published to market, but will work for development.
+     *
+     * It is configured in the dev console for the corresponding DEV_SCOPE
+     * and DEV_URL.
+     */
     public static final String DEV_CERT = "FE51F95820CDE90B5334588B1F7666A1627180CE";
+
     private final SharedPreferences sharedPreferences;
     private final Context context;