I use
Smart AudioBook Player which is $2 for the full version. It works great for MP3 Audiobooks. I use this instead of Overdrive. One feature that is awesome is it recaps what you last listen to according how long it was paused. Great if you are in that great big suspenseful scene and have to get the phone because it's an important call and forgot what the last words were. You can have multiple bookmarks just like in a real book. you can change speeds too.
I uninstalled Akimbo after finding this gem.