My friend group loves playing nonograms and competing against each other, but we always send each other screenshots of the solved game grid and time after the fact.
So from the start, I knew I wanted leaderboards, replays, and shareable links. I also added PWA support so it can be added to the home screen on mobile and an offline play mode.
No ads, analytics or nonsense, just nonograms.
Some other goodies as well such as YouTube-like scrubber and KDE-based visualization in replays.
https://github.com/siraben/nonograms/
Tech stack: React + TypeScript on Vite, hosted on Cloudflare Pages with D1 and Workers