Have you checked out Microsoft Band? Carl and Richard talk to Charles Stacy Harris about his work building Band apps. The Band is stuffed with sensors, strapped to your wrist, which opens the door to a ton of interesting information. Stacy talks about several programming options for the Band, including the web tiles that will essentially push an RSS feed onto the band. There's also SDK development options for the Microsoft Health app that communicates with the Band and works with iPhone, Android and Windows Phone. You can work natively or with cross-platform tools like Xamarin, so there are lots of choices - The Band is a great wearable device to explore!