WebDriverAgent is a WebDriver server implementation for iOS that can be used to remote control iOS devices. It allows you to launch & kill applications, tap & scroll views or confirm view presence on a screen. This makes it a perfect tool for application end-to-end testing or general purpose device automation. It works by linking XCTest.framework and calling Apple's API to execute commands directly on a device. WebDriverAgent is developed and used at Facebook for end-to-end testing and is successfully adopted by Appium.