Hey there, thanks for he feedback. About being able to "cheat" by grabbing a particularly distinct part of the puzzle and dragging it around: that is kind of the point hehe. The idea here is, after trying many times a puzzle and getting familiar with the solved piece, you should be able to tell pieces apart from each other more easily so you don't have to use only one piece as a "pivot" to solve the whole thing. So this is kind of a speed run puzzle game (I guess?)
Aside from that, I have some good news : This is now working on Android and I'll release the APK today or tomorrow :) (along with some other updates)