walk and charge

I was sitting in Intro to Adaptive Physical Activity and Mrs. Arnhold told us about this new technology that was in the news. I don't know if it was just for people with leg disablilities or everyone. Its a device that you put on your leg and as you walk and you can charge your phone. So if one lived in a more poor society that does not have much electricity it is easy for them to charge their cell phones and computers just by taking a walk. It's a way to get exercise and charge your appliances. I thought that was neat piece of technology.