Back in 2017, I made a website called Book Buddy that was a "fitness tracker for reading". A redditor found about out it on /r/books, and we did a little interview together, which you can find here.
I made this at a time where I was particularly gung-ho about forcing myself to read. Since I've never been a bookworm, treating reading like exercise felt like a good idea.
The app is no longer live, but here are some screenshots that show how it worked:
I felt like this app combined things that already existed at the time: a "tracking" interface similar to Github commit history or any habit tracking app, a rich text editor, etc. I left it in a place where I felt like it didn't do any of those things particularly well. At the very least, it sure was prettier and nicer to interact with than Goodreads.