There are a number of popular and open source tools and frameworks for testing your mobile apps. A few of the most common include :
Espresso : Android-specific and geared towards developers (recommended by Google).
XCUITest : iOS specific and geared towards developers (recommended by Apple).
Appium : Cross-platform and easy to use, with strong community support.
Calabash : Cross-platform with support for Cucumber, Xamarin-based and also easy to use.
