Parallel Kingdom is a Google Maps based role playing game for Android and iPhones that uses GPS to create a virtual world on top of a map of the real world.
In the game it is possible to attack, chat and interact with your friends and anyone else around you. Currently the game is free to download.
The game lets users claim territory by placing flags to mark locations. Players get to fight non-player characters and other players, gather resources and interact with other players.
There are global and regional ranking lists, so players can judge how well they are progressing both locally and against the rest of the world.