Also I installed a bunch of free Sudoku games on my phone and got very (and I mean very) annoyed by the un-dismissible ads and calls to actions.
So, I vibe coded an ad-free Sudoku app for the browser (a kind of PWA that plays on a phone browser too). The AI helpfully came up with a system for ranking Sudoku puzzle difficulty (by which strategies are required to solve). I'm at the point where Easy is doable, and Medium does have some challenge to it, but the Hard, Harder, Hardest puzzles required me to use strategies I have not mastered yet.
So, I added a Learn button, a show-me how button, and a notes feature. My wife and daughter gave feedback, so I fixed some usability issues (I am no UX designer).
Anyway it is open source, MIT licensed, with a link to the repo in the footer.
Posting this to see if anyone finds useful the Learn, Show-me, and Notes features (including having the game fill in the notes for you if you want).
I do not consider this a one-shot code-an-app project, because it went through many iterations and some user testing. If you think this is AI slop, let me know why. I found it useful for the prolem I was trying to solve. I have gotten better/faster at solving hard sudokus.
Also, it is not "judgy," i.e., it counts mistakes but does not kick you out after 3 strikes.
It also tracks progress and an interrupted game in local browser storage.