Docker can be used to run Android applications and tests in isolated environments called containers. This allows building and testing Android apps on any machine quickly by avoiding the need to manually install Android SDKs and other dependencies. The document discusses how Docker solves problems like setting up continuous integration environments and running UI, unit and other tests in parallel. It provides examples of fully dockerizing an Android project versus connecting devices or emulators to Docker containers. Code examples are shown for building Dockerfiles and scripts to run tests inside Docker containers.