Feature request: Track "read"/finished books
Related to #11 (closed), but a slightly different purpose.
It would be useful if Gnome Books could mark when you've "finished" a book. That way you know which books you've read and which you haven't.
The Kindle does it by showing a "percentage read" as an overlay on each book cover, but something more binary (such as a tick on finished books) would also work.
Bonus feature: Filter by read/not read (having both options would be useful so that you can do both "Book by X that I read" and "Book by X that I haven't read")