Folder Player Pro is a directory and file-centric musicmp3 player and is a more advanced version of its popular free counterpart. 
It adds the following capabilities on top of free version:
- Priority updates
- Unlimited tagging, allowing you to create multiple "playlists"
- Extended cross-fading functionality
- Ability to auto-delete tracks during playback
- Option to stop on power loss
- Option to continue playback for next folder, after current folder finishes
- M3U support
Some of the other