I'd like to see on how many days did I actually read the book.
Now when you go to "view read history", it shows the time period between start and finish, e.g. took 28 days, when I actually only read it at 19 different days.
This also is a stat I'd like to see easier, without going to history.
Maybe when you mark a book as finished, it could tell you how long it took and how many days were you reading.
I do realize that this information might be too much pressure for someone, but maybe this could be a feature you can toggle on/off ?