JazzIn: Sudoku and Killer Sudoku with hints that teach the logic

JazzIn is sudoku the way it should be: every puzzle can be solved with logic alone, step by step, without guessing. Beginner, Easy, Medium, Hard, Expert and Extreme. Each level is defined by the techniques it needs – from hidden singles to X-Wing, Swordfish, chains and, in Killer, innies and outies – so the difficulty grows smoothly and fairly. Stuck? A hint shows the next logical step and names the technique behind it, so you learn instead of just filling in a number.

Hi Product Hunt! I'm Arvydas, a solo developer from Lithuania, and I built JazzIn because most Sudoku apps either fill in a digit for you or give a hint you can't learn from. In JazzIn every hint names the technique (from hidden singles to X-Wing, Swordfish and chains) and shows exactly why it works, in three steps: a nudge, the technique, and the full explanation. The point is that you get better at solving, not just finished. It also has Killer Sudoku (cage logic, 45-rule, innies and outies), Diagonal and Jigsaw variants, a daily puzzle, light and night looks, and 44 languages. It's free with ads; Premium is optional. I'd love to hear which techniques you want explained better and what's missing for you.