Yeah, it also monitors your workouts and pulse rate, shows you call, text, and calendar notifications, functions as an alarm, keeps track of your steps per day, and calms you with breathing exercises too...but let's focus on the sleeping thing for now.
Get it from Amazon or Walmart for $129. Available in six colors and two sizes.
Promising review: "As everyone knows, it's a great tool to monitor workouts and encourages movement, but I have to say my favorite feature is the sleep tracking. I've always known that I'm not a great sleeper, but having the graphs to show when I'm awake, in light sleep, REM, and deep sleep is very informative. When I sleep well and the sleep tracker confirms it, I do what I can to replicate those particular conditions (i.e., room temp, specific white noise sound, use of blankets, etc.). It has a vibrating alarm designed to keep you from waking a partner up when you need to get up. My husband sleeps like a rock (and wore this one night for kicks, which confirmed he's a VERY sound sleeper), but I like having it because it feels more considerate." —Chellebelle