Examples of current apps include:
http://evfinder.com/evsites.htm
http://www.recargo.com/
http://drivealternatives.com/
http://www.plugshare.com/
http://carstations.com/
The Department of Energy maintains a database of EV charging station locations. EV owners are able to use the Alternative Fueling Station Locator Map to locate and route to charging stations, as well as add new stations.