Setup proguard.

app/android/app/build.gradle

@@ -59,8 +59,25 @@ android {
     buildTypes {
         release {
             signingConfig signingConfigs.release
+            // Enables code shrinking, obfuscation, and optimization for only
+            // your project's release build type. Make sure to use a build
+            // variant with `debuggable false`.
+            minifyEnabled true
+
+            // Enables resource shrinking, which is performed by the
+            // Android Gradle plugin.
+            shrinkResources true
+
+            // Includes the default ProGuard rules files that are packaged with
+            // the Android Gradle plugin. To learn more, go to the section about
+            // R8 configuration files.
+            proguardFiles getDefaultProguardFile(
+                    'proguard-android-optimize.txt'),
+                    'proguard-rules.pro'
+
         }
     }
+    namespace 'de.quantumphysique.trale'
 }
 
 flutter {

app/android/app/proguard-android-optimize.txt

@@ -0,0 +1,53 @@
+# Flutter
+-keep class io.flutter.app.** { *; }
+-keep class io.flutter.plugin.** { *; }
+-keep class io.flutter.util.** { *; }
+-keep class io.flutter.view.** { *; }
+-keep class io.flutter.** { *; }
+-keep class io.flutter.plugins.** { *; }
+
+# Retrofit
+-keepattributes Signature
+-keepattributes Exceptions
+
+# Other
+-keepattributes *Annotation*
+-keepattributes SourceFile, LineNumberTable
+
+# Logging
+-assumenosideeffects class android.util.Log {
+    public static *** d(...);
+    public static *** v(...);
+    public static *** i(...);
+    public static *** w(...);
+    public static *** e(...);
+    public static *** wtf(...);
+}
+
+-assumenosideeffects class io.flutter.Log {
+    public static *** d(...);
+    public static *** v(...);
+    public static *** w(...);
+    public static *** e(...);
+}
+
+-assumenosideeffects class java.util.logging.Level {
+    public static *** w(...);
+    public static *** d(...);
+    public static *** v(...);
+}
+
+-assumenosideeffects class java.util.logging.Logger {
+    public static *** w(...);
+    public static *** d(...);
+    public static *** v(...);
+}
+
+# Removes third parties logging
+-assumenosideeffects class org.slf4j.Logger {
+    public *** trace(...);
+    public *** debug(...);
+    public *** info(...);
+    public *** warn(...);
+    public *** error(...);
+}

app/android/app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
     package="com.gitlab.mobilemovement.trale.app">
    <application
         android:label="trale"
+	android:usesCleartextTraffic="false"
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name=".MainActivity"