What's a good Android app for tracking my sleep patterns, you know, to see if I'm actually getting any rest?

So, I've been trying out Glory Fit to monitor my sleep. You know, as a teacher, a good night's sleep is crucial, but between grading papers and worrying about lesson plans, it's often elusive. This app connects to my smartwatch, and, surprisingly intuitive, even I could figure out how to sync it up. It tracks when I fall asleep, when I wake up, and even estimates how much deep sleep I'm getting. It's not perfect, mind you – sometimes it thinks I'm asleep when I'm just reading in bed – but it gives me a general idea. It's like having a teaching assistant in your pocket, but for sleep! My students showed me a trick for setting sleep goals, which I found helpful. Why do they hide the settings button there? Honestly, once you get the hang of it, it's been a useful tool in trying to improve my sleep habits. Now, if only it could grade papers for me...