Parents in my son's hockey league used to track shots on goal with pen and paper during games, to help coaches both during and after the games. It was tedious and the data was hard to use afterward.

Not a developer, so I used AI to build a free web app to replace it. You tap where on the rink each shot came from, tag whether it was a goal or save, and at the end of the game you get a full report with shot maps, heatmaps, and per-player breakdowns. Works on your phone, no account needed.

It's not fancy tech, but it's pretty rewarding to see it actually in use by the team and now even spreading to other teams in the league :)