Application provides data on your movements. I was surprised to learn that I moved a lot in my sleep, more than 30% of my sleep time showed high levels of movement. It has a test function that lets you test it while awake to get an idea of how you movement registers on the graph. Too bad I lost my N900 in the Frankfurt airport at gate C13 and some sonofabitch has it. The serial number is 356938/03/009278/ .