Though it's a bit late to the party, Amazon is entering the competitive fitness tracker space with its new Halo Band wearable and corresponding Halo app — complete with a subscription service, because you need another one of those. Amazon's version takes a decidedly low-tech angle compared to other options on the market, skipping the screen for a bunch of sensors, a benefit that provides up to seven-day battery life. It'll even use a microphone to record your "Tone" throughout the day and determine the "energy and positivity in a customer’s voice," and the app can use its camera to measure your body fat percentage.