The Amazon store app is optimized for the iPhone 5, iPhone 6 and iPhone 6+. Using iPhones that are unable to run iOS 7.0 or later causes problems when trying to use the app.
The reviews for the app are mixed. Some reviewers have had problems with the package tracking, calling it ambiguous and not straightforward about the package delivery time. Other reviewers have called the app well-designed, but have complained about not being able to rent videos from it. The newest update of the app, as of March 2015, is version 4.4.2 and has a size of 34.3 MB.