Greetings from Wonder People!
The only way to use a single account across multiple devices is to link your game account with a Facebook account. If you have linked your game account with a Facebook account, all you have to do is to log-in with said Facebook account and you will be able to continue to play the game with said account. Please be advised that there is a limited amount of things we can do if your account is not linked with a Facebook account and is lost.
If you have any more inquiries and/or feedback, please let us know. Thank you.