https://cantunsee.space is a cool website/game where you need to spot subtle errors in the designs shown. Miniscule misallignments, wrong fontweight, etc. Takes about 10 minutes to do all the steps.
Post your score in the comments, would be fun to see what the maximum score is!
Note: Not MY project, so I’m not sure it I’m allowed to post it here but I couldn’t find a better place.