To play on different devices you need to use Facebook login.It is available right in the game. Tap the gear button in the upper left-hand corner of the screen, go to the second tab (with a skull icon) and sign in with your Facebook account. From then on your game progress will be saved on a Facebook cloud. Note, this option requires Internet connection. 

We also recommend you install Facebook mobile app on both devices and log in there with the same Facebook account you use in the game. To load your progress on another mobile device you simply need to launch the game and log in with the Facebook account you used to save progress.

Remember: game progress is saved when you quit the game. So before you start playing on device B, close the game on device A.