How can I play on multiple devices at once?

You can play on multiple devices at once in case you sync your games using your Facebook account, which is the main way to sync your progress. If you play on an Apple device, you can also use your Apple ID data to sync your progress across other devices on the same platform. 

Using the synchronization, you can play the game on several devices at the same time and have the same progress and items on all your devices.