(Before you read make sure your running IOS 11 and Xcode 9!) Connect your device (Via USB), once you do go on 'Add Additional Simulators' (See image 2 at the bottom), and tick 'connect via network' (See Image One). Once XCode proccesses this, disconnect the device (via USB) and it should now appear with a globe next to it (See image 2)! Also make sure the device and computer are on the same network!