Foursquare is a location-based social networking website for mobile devices, such as smartphones. Users "check in" at venues using a mobile website, text messaging or a device-specific application by selecting from a list of venues the application locates nearby. Location is based on GPS hardware in the mobile device or network location provided by the application, and the map is based on data from the OpenStreetMap project. Each check-in awards the user points and sometimes "badges". The user who checks in the most often to a venue becomes the "mayor," and users regularly vie for "mayorships."The service was created in 2009 by Dennis Crowley and Naveen Selvadurai.