Sleep as android

Yesterday was my first trial of the app called "sleep as android".
Sleep as android is an alarm clock app which can also monitor your sleep.
It does it using the phones gyroscope, you lay your phone on you bed next to you, and during the night, whenever you move, the phones sensors pick it up, judging by the amount of movement, it knows whether you are in a light sleep or deep sleep stage.

My two graphs so far:

I am planning on using it for another week, and if I like it, buy the full version.

One possible experiment I may conduct is to see the effects of meditation before bed on the quality of my sleep.

I could also see if I avoid computer screen light before bed, it improves my sleep.