I think, that it would be a nice edition to make it so you can also earn free diamonds, as diamonds are very important in the progression in the game, and are a pain to get, as theres no good way to really AFK them at all. So, like the stars, coins, etc, cheats. I think that you should add ones that adds diamonds for the shop, challenges, etc. 
I think, that it would also be pretty cool, if you could input your own mods, maybe like a reskin mod maybe? This could be pretty niche, as it would make it way easier to change stuff in the game without having to edit the files, getting third party software, etc.