Speed - Measure your Speed. Speed shows you current/max speed going down a mountain in powder, jumping off a cliff skydiving, out on the sea or just driving your car. Mph. Km/h. Knots. M/s. Ft/s. Info: Buying or using my apps guarantees support. Note: Works ONLY with Android Wear. More info: Start the the app in your Wear watch, enable GPS on your Mobile phone.