Appium is an open source, cross-platform automation testing tool for both iOS and Android apps. Appium is a free mobile testing tool and available as an open source from GitHub. It has easy integration with Selenium Web Driver, that’s what makes it more famous. Now, why do you need it? It would depend solely on your requirements. But first of all, you’ll need to understand when you should use Appium. For example, if you are an application developer or a mobile app tester who wants to verify his app on multiple platforms. Then Appium can help you in doing that. If your app is only for a single platform, then it’s not worth putting efforts in learning and using Appium for test automation. It was only restricted to the mobile application testing. It is used for automating test cases for Native, Hybrid and Web based applications.