I've seen and got PM'd this question multiple times, I copied this from the support thread because not many people read it
1.Go to iOS Settings — iCloud and log out from iCloud on both devices.
2.Log in back to iCloud account on device with game progress you want to transfer (#1).
3.Launch King of Thieves on device #1.
4.Make sure iCloud is turned on in game options.
5.Log in to iCloud on another device (#2).
6.Launch King of Thieves on device #2.
7.You should see game progress transfer popup.
Don't thank me, thank Chervey
Note: you CANNOT transfer from Android to iOS or vice versa, it must be the same compatibility of device!
Edited by JackBowe, 14 August 2015 - 07:47 PM.