In order to transfer the game data, you need to connect your game to a Facebook / Google Play / Game Center account. If you don't have a Google Play or Game Center account we recommend you to connect your game to Facebook. Connecting your game to Facebook also enables you to play the game on desktop. If you change between devices that has different softwares (Android to iOS, iOS to Android etc.), Facebook connection is recommended as well.
To complete the action please follow these steps:
Go to Settings > Social in the game and choose "Connect" button that has the Facebook / Google Play / Game Center logo on. After connecting your game to an account, you can recall your game in your new device by going to Settings > Social > Switch.