Great service but horribly designed and confusing, maze-like app which makes it harder to find books, see how they interrelate, discover series and explore links between authors, narrators etc. The app appears to be increasingly designed to disoriented you into making more purchases and clicking on more free books and podcasts. It is the IKEA model executed very poorly. I would say that Amazon should hire usability experts to redesign the app, but I think this design is wholly intentional.