Audiobook Player 2 is one of the most popular audiobook apps with over 100,000 downloads. The application has four and a half star rating with 849 users voting, so it must be pretty good.
One major issue which was a deal killer for me is that it only supports mp3 files, not m4b or m4a files which is what I like to use.
There is a free version of the app which has ads and a paypal donation installed. These take up a lot more memory, so there is a paid version which is smaller and elimates the annoying ads and paypal requests. The paid version costs $4.81 and is five times smaller than the free version.
Reading through the reviews, users either love the app or hate it. So I think the only way to know if you will like it is to try it.