Features:
* Chromecast support.
* Playback speed control.
* Classification of books (new, started, finished).
* Download cover from the Internet.
* List of characters. You can manually create a list of characters to easier follow the story.
* Automatic pause in case you fall asleep. To continue playback just shake your phone.
* Playback history.
* Application Widget. Allows you to control the player from the home screen.
* By specifying a root folder containing all your audiobook, you can exclude your folders which contains music and other audio files.
* You don't have to finish one book to start another. The progress is saved independently for all books.
Requirements: Android 6.0+
Home Page -

https://play.google.com/store/apps/details?id=ak.alizandro.smartaudiobookplayer&hl=en