WebDriverAgent can be started as any UITest bundle. We recommend using Xcode, xcodebuild or FBSimulatorControl. In order to start any UITest you need a test hosting application, which is used only to run test runner code and it should NOT be tested application. Xcode and xcodebuild will prepare test hosting application for you, however with FBSimulatorControl you need to use your own and point it explicitly or use system applications e.g. Safari.

After WebDriverAgentRunner is launched, you can get service URL from device logs (or Xcode console). Just search for line:

ServerURLHere->http://[SOME_IP]:8100<-ServerURLHere

Simply open WebDriverAgent.xcodeproj and start WebDriverAgentRunner test.

xcodebuild -project WebDriverAgent.xcodeproj \
           -scheme WebDriverAgentRunner \
           -destination 'platform=iOS Simulator,name=iPhone 6' \
           test

Build WebDriverAgent.xcodeproj and then:

./fbsimctl --state=booted \
           launch_xctest [path]/WebDriverAgentRunner.xctest com.apple.mobilesafari --port 8100 -- \
           listen

Checkout FBSimulatorXCTestCommands.h and use sample in tests