If you like solving sudokus, and I'd be a bit surprised if you're here and don't :-), you might want try the app "Sumaddle" [1] available on (at least) iOS. It'

If you like solving sudokus, and I'd be a bit surprised if you're here and don't :-), you might want try the app "Sumaddle" [1] available on (at least) iOS. It's a different kind of puzzle, but a very similar "get to a point where you can't figure out how to go forward, then realize there's a clever inference available" vibe. 1: https://apps.apple.com/us/app/sumaddle/id1552172214 https://apps.apple.com/us/app/sumaddle/id1552172214