Apparently they do. As of Android Jelly Bean 4.2.2 the concept of "day dreams" has existed. A day dream is basically a screen saver that runs when your device is charging or docked.
With this in mind, I thought it would be cool if there was a daydream that allowed you to control playback of the Rdio app, and looked cool. So that's what DreamPlayer is. A simple, clean player that pulses to the music when your Android device is dreaming.