We've said it before: you spend more time sleeping than doing anything else, so getting the most out of your shut-eye time is important. The Samsung Sleepsense Sleep Tracker can help you do that. This thin, circular device slides under your mattress, and uses a contactless sensor to track your heart and respiratory rates, as well as your movement. In the morning, the companion app gives you a sleep score that's based on seven different factors, and even suggests things you can do to improve it, based on guidance from a Harvard Medical School professor. It can also connect to smart appliances, doing things like controlling your A/C and turning off your television, and can gently wake you at just the right time to help you get the most out of your mornings.