MacRumors:
https://www.macrumors.com/2018/01/25...gned-book-app/
Good luck with that, Apple, but I don't think it's going to be successful. You might attract some die hard Apple fans who are casual readers. But I can't see serious readers (those who buy a lot of books) willing to leave the established already successful channels.
To me, a good bookstore has to be more than a convenient app.