This Tiny Device Uses Your Body’s Motion To Charge Your Phone

Using kinetic energy (running, biking, parkour) to fuel itself up, AMPY is the world's smallest wearable motion charger available today. The way this black magic works is extremely simple: latch your AMPY onto your arm or leg before starting to exercise, as you begin moving, AMPY turns your movements into battery power, just like an automatic watch. Once full, AMPY will give your phone 18 hours of battery life.

If you download their app, you'll be able to sync AMPY with your phone and track how many calories you're burning, how much battery life is left, and how much energy your movements are generating. 

And if you're tremendously lazy and hate exercising, AMPY can be recharged by any wall outlet or standard USB cord, making it an excellent option for a backup battery when you don't feel like getting off the couch to grab the charger in your room.