Unfortunately Amazon tends to make their Kindle app and firmware in such a manner that overly emphasizes features designed to sell more books and under-emphasizes reading those books. Welcome to corporate America! I have a basic Kindle but mostly read on my Kindle app via my two iPads. I really don't need nor want about 90% of the interface features Amazon has included. Those features merely clutter up the interface and annoy me. I wish they were just barebones type of apps, but then Amazon wouldn't make a fortune off of us so the book selection would likely be meager. At any rate I stick with Amazon Kindle books because their cloud actually works and they have a huge selection of books, unlike any of their competition. Fortunately Apple has greatly improved the act of reading on their devices and that more than compensates for Amazon's lackluster formatting options in their app.
Anyone else old enough to remember when reading was about the words and not about devices, firmware, and library features?