MagnifiSense is a high-tech wristband developed by University of Washington researchers. Unlike fitness trackers, though, it doesn't log the number of steps you've taken or calories burned: it takes note of the electronics and appliances you personally use to keep track of your power consumption. During their tests, the researchers found that the sensor can correctly identify and differentiate 12 devices from each other, including electric toothbrushes, lamps, laptops and even cars. It's able to tell them apart by "listening" to the electronic radiation they generate. According to lead researcher Edward Wang, electronics actually produce distinct sounds similar to "vocal cord patterns," so "a blender 'sings' quite differently than a hair dryer."