The backup and restore capability is a feature of the Android operating system that Google implemented with Android 4.0 and later. It is not activated from the game, but rather it is an automatic feature that you enable in the operating system. It is active as long as you have a version of the Android OS that supports it, and you have properly set up automatic backup and restore in the settings on your device.

Note that the following procedures may vary somewhat, depending upon the device and carrier, as well as the version of Android installed.

To turn on automatic backups, choose Settings > Privacy and check the "Back up my data" and "Automatic restore" checkboxes, making sure that you have set the appropriate account(s) for backup. If you don't see those options on your device, you are likely running an older version of the Android operating system and won't be able to use this feature.

Once you have made sure that backup and restore are properly set up on your device, the game will be automatically backed up each time you play it. Should you delete and reinstall the game or install it on a new device, your saved data will be automatically restored as long as you are logged in with the same user account that you used for backup.

If you are uncertain how to use these features, please consult your device's owner's manual or online help for further information on setting up and using Google's automatic backup and restore features.