Plenty of fitness trackers offer sleep tracking, but many of us would prefer not to wear anything to sleep. The Beddit Sleep Monitor overcomes this by hiding itself under your sheet. The first release since the company was purchased by Apple in 2017, it automatically measures sleep time, heart rate, breathing, snoring, and bedroom temperature and humidity, sending its analysis and heart rate data to the Health app on your iPhone. You can also set it to provide sleep reports, bedtime reminders, and tips, and at just 2mm thick, you'll likely never even notice it's there. A perfect nighttime companion for your Apple Watch.