I don’t know how I feel about sleep tracking. I’ve been using such an app for months now and I’m usually very surprised by the results. In my opinion, it tends to overestimate my sleep quality. Sometimes I’d wake up from an awful night full of nightmares, tired and only wanting to go back asleep and get some rest, and the app would rate that night 91/100.
It does seem a little crazy to think you can get precise data juste by using the microphone of your phone or any other kind of ways to detect movement. Sleep is such a complex mechanism, and trying to understand it by only using movements doesn’t seem like the right approach.
I end up tracking my sleep for only one data that is roughly accurate all the time: the amount of time I slept. It just makes it easier to read the number on the app than to do the math every day.