Audiobooks from Audible is the official Android application to be used with the service provided by Amazon. Using this software, you will gain access to a huge library of audiobooks. As you probably expect, you need to add the credentials for your account to start using this application. When it comes to its user interface, you will have to work with a well-organized layout, and you shouldn't run into issues.
Audible does a good job of recommending you new books, but you can also use the searching function to find new stuff. The application allows you to choose the narration speed by adjusting the slider and to download books for offline use. This is a great small feature because you don't have to be connected to the Internet all the time.
Just download a couple of audiobooks and listen to them while traveling and so on. Each member gets 2 Audible originals each month. You can also configure a sleep timer depending on your needs. Another neat feature of this application is that you can synchronize your audiobooks across multiple devices.