There are many other forms of testing that you can incorporate into your development lifecycle. These other tools are outside the scope of this book, but are listed here for easy reference and future exploration.
Here are the Android sanctioned ways to test.
You use Junit style tests and create a test application that runs with your normal application. The test application exercises the user interface.
It can be great for functional or integration testing, but since it relies on an emulator, it's just too slow for as-you-are-building-a-feature testing.
http://developer.android.com/tools/testing/testing_android.html
This testing framework runs on the device and uses accessibility features to conduct functional testing.
http://developer.android.com/tools/help/uiautomator/index.html
This framework allows you to script test in Python and runs your tests on an emulator. http://developer.android.com/tools/help/monkeyrunner_concepts.html
There are many tools out there. Each application may lead to a different selection!