Selendroid is an open-source test automation framework for mobile applications. It is specifically designed to automate UI testing for Android devices, including both native and hybrid applications. Selendroid provides a WebDriver-compatible API, making it easy to write tests using Selenium WebDriver syntax.

Here are some key features and functionalities of Selendroid:

1. Android Application Support: Selendroid supports both native and hybrid Android applications. It allows you to automate interactions with UI elements such as buttons, text fields, checkboxes, and more.

2. Multiple Android Versions: Selendroid is compatible with various Android versions, from 2.3 (Gingerbread) to the latest versions. This enables you to write tests that can run on a wide range of Android devices.

3. Cross-platform Testing: Selendroid supports cross-platform testing, allowing you to write tests that can be executed on different Android devices and emulators.

4. Inspector: Selendroid provides an Inspector tool that helps you inspect the UI hierarchy of your application. It allows you to identify elements and their properties, which is useful for locating elements during test script development.

5. Advanced Interactions: Selendroid supports advanced interactions such as multi-touch, gestures, swiping, and zooming. You can simulate various user actions to test different scenarios and user flows.

6. WebView Testing: Selendroid enables testing of web content within a WebView component in hybrid applications. It supports automating interactions with HTML-based content loaded within the application.

7. Test Framework Integration: Selendroid integrates with popular test frameworks like TestNG and JUnit, allowing you to structure and execute your tests using these frameworks. You can use assertions and annotations provided by the test frameworks to perform validations and manage test execution.

8. Continuous Integration: Selendroid can be seamlessly integrated with continuous integration servers like Jenkins or Bamboo. This enables you to automate test execution as part of your build pipeline, generating reports and capturing test results.

It’s important to note that Selendroid is no longer actively maintained as a standalone project. The developers have shifted their focus to Appium, another popular mobile test automation framework that supports both Android and iOS platforms. Appium provides a more robust and widely adopted solution for mobile automation testing.