It just literally did not function for me (i.e. buggy software). One of those Kickstarter projects :/
This isn't really for sleep tracking. It's for sleep retraining. Basic premise is that falling asleep is a skill you can practice like any other, but it's hard to do that because you... well... fall asleep.
So this device is meant to ask you whether you're awake every minute (you say yes by tapping your finger) and once you stop responding, it triggers an alarm to wake you up. By waking up and falling asleep again repeatedly, you learn to fall asleep better.