It's built on React-Native. I used mobx as a game engine. It was fun and challenging.

I created promo codes for HN, so you can download it free :)

Promo Codes: https://www.appcodes.com/d/nuzzle-sudoku-puzzle

App Store: https://itunes.apple.com/us/app/nuzzle-sudoku-puzzle/id12427...

Trailer: https://www.youtube.com/watch?v=6KdId2Y9Szg

App Advice Review: https://appadvice.com/post/line-up-your-numbers-right-in-nuz...

Product Hunt: https://www.producthunt.com/posts/nuzzle-2