Fills Missing Function
Even though both the iBooks app (as of iOS 8.4) and the Audible.com Audiobook player are supposed to play custom MP3 audiobooks, they do it poorly. iBooks insists on calling all the books "Track 1", "Track 2", etc instead of by their actual names. And Audible calls every book "Part 0", a bug that has been around for a while now.
MP3 Audiobook Player does a great job playing custom MP3 audiobooks. Not only does it have all the features of the other players, but it also handles the files extremely well, properly displaying the names and sorting them as intended.
Dale Reeck about
MP3 Audiobook Player Pro