The Wahoo RFLKT is an iPhone-controlled bike computer that wirelessly receives images and data from the iPhone located in the jersey pocket of a cyclist. Mounted to your handlebars, it’s the size of a cycling computer and has side buttons to control the app, screens, start/stop timer, and even music, among other things. The RFLKT weighs just 2 ounces and measures 2.4 inches long by 1.6 inches wide and 0.5 inches thick. The device uses a Bluetooth 4.0 connection and has more than a year of battery life. It’s compatible with the iPhone 4S and iPhone 5.