Buoy is actually two things: the device and the app. The device is the blue cylinder that attaches to the main water input at your home. Water flows through the device, which is connected to your home WiFi network, and sends data to the app. The app categorizes your water use data and shows you where you’re using water, so you can take control of your water use and avoid surprise water bills. You can shut off your water using the red button on the Buoy device or, remotely, from the red button in the Buoy app.