Fully Metadata-Driven Apps
You can develop applications that rely purely on configuration. You can develop a fully metadata-driven app by describing the UIs, data bindings, screen transitions, and actions in the layout XML.
The Extensibility Framework resolves the bindings, creates the UIs and
inserts them into the navigation chain, and manages the default actions when the device
user interacts with the controls.
If you set up the layout XML correctly, the app is fully functional as soon as you add a few lines of code to the app delegate, as described in Loading the Library.