Gateworks supports Android on the Ventana family of Single Board Computers. Once loading Android onto the SBC, the next logical step is to create an app. Some of these apps may want to communicate with a GPIO and other hardware. Gateworks has documented some examples and tutorials on creating a simple Android app and correctly integrating it into the system.
Please find all the information on the Gateworks Software Wiki link: http://trac.gateworks.com/wiki/Android/app_development