Declare game controller support

Android

Declare Game Controller support in your AndroidManifest as follows:

<uses-feature android:name="android.hardware.gamepad" android:required="false"/>

This is not really required, but may be used by Play Store or Launchers in the future.

iOS

From iOS 14 on, Apple shows a badge on your App Store entry if your game declares game controller support.

Add the following lines to your Info.plist.xml file:

<key>GCSupportedGameControllers</key>
<array>
    <dict>
        <key>ProfileName</key>
        <string>ExtendedGamepad</string>
    </dict>
</array>
<key>GCSupportsControllerUserInteraction</key>
<true/>

Note: Apple enforced the functionality of Pause/Start button in the past. This seems to be loosened nowadays.