It is possible to play Sniper Strike across multiple devices on the same platform i.e. Multiple iOS devices at the same time or Multiple Android devices at the same time. However, it is not possible to play across platforms i.e. iOS > Android or Android > iOS
In order to transfer your progress from one device to another, you must be signed in using Google Play Games (Android) or Game Center (iOS).
All you need to do is sign in with the same Google Play Games/Game Center account as you did on the previous device to restore your progress.
If you are experiencing any issues with restoring or synchronizing your progress, please submit a support ticket and we will be happy to help - Open New Support Ticket