Sung-Hyun Jang, one of my Ph.D. students here at CASA, has launched an Android app called AR Navigation System for Pedestrians.
The app is a part of his Ph.D. studies, and is an attempt at visualising geographic information via an augmented reality interface. Specifically, the app provides navigation information via both map interface and an augmented reality interface.
The app was written in Java using the Android SDK, and uses the Google Maps API and the Google Direction API. Going forward, Sung is looking to use the app to research Human-Computer Interaction (HCI) and in particular to help him investigate spatial knowledge acquisition.
You can learn more about app at http://www.pinenutapps.com/
The app is available at Google Play. (https://play.google.com/