My son put me on to an app for monitoring sleep patterns. You put your phone next to your bed at night and the app listens out for noises and decides what the noises mean. It can sense the sound of your breathing and movements and from this decide whether you are awake, asleep, in deep sleep, snoring, talking.
These are my 6 days of using the app. The sleep patterns are all over the place and I couldn’t see a relationship between the patterns and how well I felt I had slept. Also, I suspect that the awake peaks in the middle of of the night are my wife going to the loo! I’m not sure how the app can work when there are two people in close proximity to the phone. With the app draining the battery 50% or more, my curiosity is exhausted and I’ve deleted it – at no cost.