This is something I've wanted to build for awhile (first bought the domain in 2020 (then lost it for a year+)). It's a tactics solver on each new tab page.

There are 5 modes of play:

Easy (<1200 elo)

Medium (1200-1800)

Hard (1800-2400)

Expert (2400+)

Speedrun (solve as many puzzles as possible in 60 seconds).

I'm having a ton of fun with it, and definitely noticing improvements with actual games (definitely solved the most puzzles in my life while developing this extension).

If you check it out, please let me know what you think. Any feedback is good!