I built a PWA for disc golf speedruns: https://www.anhyzer.io/

I'm really quite pleased with it and I use it often, but there's only one course listed (the one I play on), and there's no feature for letting users contribute data for courses. Also, I use a database with public access, so if you know what you're doing you can hack the scoreboard.

If you're interested or want to add a course I'd accept PRs: https://github.com/staab/disc-golf