Rhythm Den app for iPhone and iPad

RhythmDen is a music player that streams music stored in your Dropbox account. Supports MP3 (.mp3) and M4A (.m4a) audio formats.

It supports the following features:

* Sortable music collection by Artist or Album
* Seach functionality
* Create music play lists from collection
* Supports background playback (you can lock your device for continuous play)
* Supports background library synchronization
* AirPlay compatible
* Notifications when streaming on their data plan
* Facebook and Twitter integration