I think it would be really useful to have the option to add personal notes to books.

As our TBRs grow, it's easy to forget why a book was added. A note could be used for things like:

• Recommended by a friend or book club
• Seen on YouTube, TikTok, Instagram, or TV
• Mentioned in another book
• Interested because of a specific trope or theme
• Saving it for a particular season or reading challenge
• A reminder to my future self

One possible implementation

StoryGraph already has a great version of this in Challenges.

When you add a note to a book in a challenge, an ℹ️ icon appears next to the book, and clicking it opens the note in a small pop-up. It's simple, clean, and doesn't add any clutter.

I could see the same approach working for books:

• Add an optional Personal Note field when adding a book to a TBR or changing its reading status.
• Show an ℹ️ icon next to books in lists (e.g. To Read, Owned, Currently Reading, Read, etc.) whenever a personal note exists.
• Display the same ℹ️ icon on the book page, next to the existing ⚠️ Content Warnings icon, so the note is always easy to find.
• Clicking the ℹ️ icon would open the note in the same pop-up used in Challenges.

It feels like a natural extension of functionality that's already in the app, while making larger TBRs much easier to manage.