This widget displays in which former sector of old time occupied Berlin you are in. Different flags indicate the sector of the corresponding occupying force.
Clicking on it will launch TheWall app when installed. When TheWall app is not installed, you are directed to the Android market where you may purchase it. The full app provides you with far more information about Berlin, the Wall, the Cold War, touristic points of interest and all leftover pieces of the Berlin Wall around the world.