I really like Polytopia, its a little turn based strategy game with loads of replay value - every game's different. IAPs are just the different tribes you can play as, nothing scammy.
Buying a tribe also unlocks multiplayer (online), which is where the game really grabbed me. Playing with the spouse and siblings is a blast. The fact that you can play the game without having to pay anything is a bonus, but paying for something was worth it.