diff --git a/OpenPGP-Keychain/build.gradle b/OpenPGP-Keychain/build.gradle
index 566559a00..852bfef38 100644
--- a/OpenPGP-Keychain/build.gradle
+++ b/OpenPGP-Keychain/build.gradle
@@ -4,8 +4,7 @@ buildscript {
     }
 
     dependencies {
-        // NOTE: Avoid using dynamic versions (+). This breaks offline builds!
-        classpath 'com.android.tools.build:gradle:0.6.3'
+        classpath 'com.android.tools.build:gradle:0.7.3'
     }
 }
 
@@ -15,9 +14,6 @@ repositories {
     mavenCentral()
 }
 
-/*
- * NOTE: Avoid dependencies from Maven. Include as much sources as possible for F-Droid!
- */
 dependencies {
     compile fileTree(dir: 'libs', includes: ['*.jar'], excludes: ['android-support-v4.jar'])
     compile 'com.android.support:support-v4:19.0.+' // already in actionbarsherlock
@@ -79,4 +75,9 @@ android {
     } else {
         buildTypes.release.signingConfig = null
     }
+    
+    // Do not abort build if lint finds errors
+    lintOptions {
+        abortOnError false
+    }
 }
diff --git a/OpenPGP-Keychain/res/values/strings.xml b/OpenPGP-Keychain/res/values/strings.xml
index ab2c638fe..190dcfa53 100644
--- a/OpenPGP-Keychain/res/values/strings.xml
+++ b/OpenPGP-Keychain/res/values/strings.xml
@@ -333,7 +333,7 @@
     <string name="import_qr_code_wrong">QR Code malformed! Please try again!</string>
     <string name="import_qr_code_finished">QR Code scanning finished!</string>
     <string name="import_qr_scan_button">Scan QR Code with \'Barcode Scanner\'</string>
-    <string name="import_nfc_text">To exchange keys via NFC, the device needs to be unlocked.</string>
+    <string name="import_nfc_text">To receive keys via NFC, the device needs to be unlocked.</string>
     <string name="import_nfc_help_button">Help</string>
     <string name="import_clipboard_button">Get key from clipboard</string>
 
diff --git a/README.md b/README.md
index 1e7cea335..6193a301a 100644
--- a/README.md
+++ b/README.md
@@ -105,6 +105,8 @@ TODO
 
 # Libraries
 
+
+
 ## ZXing Barcode Scanner Android Integration
 
 Classes can be found under "libraries/zxing-android-integration/".
@@ -151,6 +153,21 @@ See http://docs.oseems.com/general/application/eclipse/fix-gc-overhead-limit-exc
 1. Open svg file in Inkscape
 2. Extensions -> Color -> darker (2 times!)
 
+## Gradle Build System
+
+We try to make our builds as [reproducible/deterministic](https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise) as possible.
+This is also a key requirement to be part of F-Droid.
+When changing build files or dependencies, respect the following requirements:
+- No precompiled libraries. All libraries should be provided as sourcecode in "libraries" folder
+- No dependencies from Maven
+- Always use a fixed Android Gradle plugin version not a dynamic one, e.g. ``0.7.3`` instead of ``0.7.+``
+- Commit the corresponding gradle wrapper version to the repository
+
+TODO:
+[ ] include support lib as source
+[ ] include Spongy Castle as source
+[ ] resolve lint errors (currently abortOnError is false in some build.gradle files of main project and libraries)
+
 # Coding Style
 
 ## Code
diff --git a/build.gradle b/build.gradle
index 06c57cd0b..5d9739785 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,7 +4,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:0.6.3'
+        classpath 'com.android.tools.build:gradle:0.7.3'
     }
 }
 
@@ -15,5 +15,5 @@ allprojects {
 }
 
 task wrapper(type: Wrapper) {
-    gradleVersion = '1.8'
+    gradleVersion = '1.9'
 }
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 667288ad6..d5c591c9c 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index f984ebc0a..c9e50d492 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Mon Dec 30 23:22:47 CET 2013
+#Thu Jan 16 22:16:02 CET 2014
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=http\://services.gradle.org/distributions/gradle-1.8-bin.zip
+distributionUrl=http\://services.gradle.org/distributions/gradle-1.9-bin.zip
diff --git a/libraries/ActionBarSherlock/build.gradle b/libraries/ActionBarSherlock/build.gradle
index e25786733..1fed282d9 100644
--- a/libraries/ActionBarSherlock/build.gradle
+++ b/libraries/ActionBarSherlock/build.gradle
@@ -15,4 +15,9 @@ android {
       res.srcDirs = ['res']
     }
   }
+  
+  // Do not abort build if lint finds errors
+  lintOptions {
+      abortOnError false
+  }
 }
diff --git a/libraries/HtmlTextView/build.gradle b/libraries/HtmlTextView/build.gradle
index 1fd554404..8c59e4b55 100644
--- a/libraries/HtmlTextView/build.gradle
+++ b/libraries/HtmlTextView/build.gradle
@@ -1,12 +1,3 @@
-buildscript {
-    repositories {
-        mavenCentral()
-    }
-    dependencies {
-        classpath 'com.android.tools.build:gradle:0.6.3'
-    }
-}
-
 apply plugin: 'android-library'
 
 
@@ -21,4 +12,9 @@ android {
             res.srcDirs = ['res']
         }
     }
+    
+    // Do not abort build if lint finds errors
+    lintOptions {
+        abortOnError false
+    }
 }