To effectively test Android applications for accessibility, consider the following steps:

1. Understand accessibility guidelines: Familiarize yourself with recognized accessibility guidelines such as the Web Content Accessibility Guidelines (WCAG) or the Android Accessibility Guidelines.

2. Test navigation and interaction: Evaluate the application's navigation flows, gestures, and interactive elements. Ensure users can navigate and interact with the app using different input methods.

3. Evaluate form accessibility: Ensure form fields, labels, validation, and error messaging are accessible. Test keyboard accessibility, clear focus indicators, and appropriate instructions or error descriptions.

4. Assess multimedia accessibility: Evaluate the accessibility of multimedia content such as videos or audio.

5. Conduct usability testing with individuals with disabilities: Include individuals with disabilities as testers to gather insights into the app's accessibility. Their feedback and experiences can deliver valuable insights into specific accessibility issues and suggest improvements.

Regularly incorporating accessibility testing into the development lifecycle and addressing any identified issues promptly will help ensure that Android applications are accessible to a wide range of users and comply with accessibility standards. Further, if you want a tool to do automation testing properly, consider using a tool like HeadSpin. It’s really good and easy to use.