An Address Book Sample Application is  available for download on the project site. You can see screenshots, check it out in action and download sources and run application  locally.

It helps you understand how to build real applications with qooxdoo and qxtransformer, how to separate logic and presentation. It also has
integration with Google Gears and uses local database storage to store all contacts.

If you have any question you can ask them in our Google Group.