Remember that the most important thing to do with your account is to save it. This process prevents the loss of your progress, regardless of the device you are on. We have posted on our fan page a lot of times how important this is to our players. To save your account, you must link your game account with your Google main Account on the device. You need to see at least one device linked in the configuration. The same is true for iOS, you need to have your game account linked to your Gamecenter through Apple ID. This is the only way to save your account and avoid losing progress. To do it, just go to your settings in the game, then on the account tab press the “Link to device” and that's all.