@PeregrinoCinzento @TheYang
I can highly recommend (on android) LISTEN AUDIOBOOK PLAYER
It has all features of SmartAudiobook Player (possibly more), but I feel it is more polished, can use screen gestures (swipe up, down, right, left) for moving forward or back in book, or raise/lower volume.
Most importantly to me it can correctly show "chapters" in mp3 files, especially for audiobooks downloaded from Overdrive/Libby, which use a proprietary chapter tagging. SmartAudiobook Player can't
@PeregrinoCinzento @TheYang
Sirin Audiobook Player on Android is also very good and can decipher the Overdive/Libby chapters.