Endel

Instead of making you pick from a vague, spa-like list of background noises, Endel intelligently uses a range of factors to create its own. Its algorithm takes into account your location, time zone, weather, and heart rate to come up with sounds that are meant to help you focus, relax, sleep, or provide you with a tempo-based soundtrack when you're on the go. At the end of the week, it wraps all the data it's gathered into a nifty visualization, so you can see how you did, and where to improve going forward.