Sandbox Account Viewer is a sample app that demonstrates how to use AdWords API client library to display contents of an AdWords sandbox account. It can be used to visualize the effects of a request on your account and to retrieve information such as IDs that're needed when running examples. "Google decided to share this code as open source to provide a starting point for new developers and to demonstrate some of the core functionality in the API. Sandbox Account Viewer doesn't attempt to replicate the official AdWords web interface, but rather displays information exactly as it's returned by API. The objects in the account are displayed in a tree on the left, and when selected their details are displayed in a table to the right," explains Google.
To get started, download source code and open the project in Eclipse or your favorite Java IDE. Read through the README and javadoc comments to understand how the application works and use the Ant task "run" to launch it.