Back button quitting

android/src/io/anuke/mindustry/AndroidLauncher.java

@@ -52,6 +52,13 @@ public class AndroidLauncher extends AndroidApplication{
         config.depth = 0;
         Platform.instance = new Platform(){
 
+            @Override
+            public void hide(){
+                ui.showConfirm("$confirm", "$quit.confirm", () -> {
+                    AndroidLauncher.this.moveTaskToBack(true);
+                });
+            }
+
             @Override
             public void openDonations(){
                 showDonations();

core/src/io/anuke/mindustry/core/Control.java

@@ -310,6 +310,10 @@ public class Control implements ApplicationListener{
             if(!state.isPaused()){
                 Time.update();
             }
+
+            if(!scene.hasDialog() && Core.input.keyTap(KeyCode.BACK)){
+                Platform.instance.hide();
+            }
         }
     }
 }

core/src/io/anuke/mindustry/core/Platform.java

@@ -69,6 +69,9 @@ public abstract class Platform {
      */
     public void showFileChooser(String text, String content, Consumer<FileHandle> cons, boolean open, String filetype){}
 
+    /**Hide the app. Android only.*/
+    public void hide(){}
+
     /**Forces the app into landscape mode. Currently Android only.*/
     public void beginForceLandscape(){}