AudioRecall Player
Is ideal for people who listen to spoken word materials, such as audio books and podcasts. AudioRecall Player is an audio player that keeps track where you left off.
The app tracks the last playlist played. Within each playlist, AudioRecall Player shows you which track you left off on and the location within the last track played for that playlist. Another handy feature, is the ability to flag (or bookmark) locations during playback. You can make notations about the purpose of this flag and go back to this location at a later time.
As of version 2.0 Audio Recall Player has some support for iTunes' folders. It doesn't handle folders of folders. But it will handle folders that contain playlists. Which is a great way to organize books that are a part of a series or group of podcasts of a certain topic!