Appium

Appium is to mobile apps exactly what Selenium is to web browsers. It is a massive, open-source automation framework specifically designed to control native iOS and Android applications. If a company wants to automatically test their banking app by writing a script that opens the app, types in a PIN, and checks the account balance, they use Appium. Its absolute biggest philosophical advantage is that it doesn't require developers to recompile their app. Historically, mobile testing tools required developers to inject a "testing SDK" directly into the app's source code, which meant the app being tested wasn't exactly the same as the app being shipped to the App Store. Appium interacts with the exact, unmodified production app. It is completely cross-platform. A developer can write a single automated test script in Java, and use Appium to execute that exact same test against both the iOS iPhone version of the app and the Android Samsung version of the app simultaneously, cutting the required QA engineering work perfectly in half.