I like the Number challenge type. I think it would be really cool if the number is counting something that StoryGraph tracks, it could automatically add books. For example, I have a challenge to read 30 Non-Fiction books this year. When I set up the challenge, it would be really cool if I had the option to associate the challenge with the Non-Fiction genre. Then when I read something of that genre, it would automatically add it. That way, I wouldn't have to go in and add each individual Non-Fiction book one by one. There could still be the option to add everything manually for number challenges that don't correspond with something StoryGraph doesn't track.