BlindSquare is the 2012 Open Cities app Challenge Winner

BlindSquare is an augmented reality GPS application for the blind.

BlindSquare makes you sense what's around. You only need to be a good listener. It obtains information about the surrounding environment from FourSquare and Open Street Maps. It’s algorithms enable it to determine the most relevant information, and then voice it out using high quality speech synthesis. For example, “What's the most popular café within 200 meters radius?”