The Android operating system has grown significantly since its introduction in 2009, with over 71% market share today. As a result, testing for Android devices is crucial to ensure compatibility and quality. Manual testing involves putting an application on a physical device and running it end-to-end, while compatibility testing addresses the vast range of Android devices and their varying specifications. Automated testing using frameworks such as Selenium, Appium, and Espresso can be used to perform user interface tests and unit tests, which isolate individual methods of code to exercise small bits of logic. Continuous Integration systems facilitate automated testing and performance testing, including load testing and soak testing, while Security Testing involves scanning source code and penetration testing. Sauce Labs provides a cloud-based platform for Android app testing, offering virtual devices, automation tools, and integrations with CI servers.