Foursquare launched in March 2009 at the SXSW Interactive Festival in Austin, TX. It is a location-based mobile platform that makes cities more engaging to explore. By checking in via a smartphone app or SMS, users can share their location with friends while earning points and virtual badges.
In November 2009, following a round of angel funding from investors including Union Square Ventures and O’Reilly AlphaTech Ventures, Foursquare launched its API. At the time, an impressive set of applications had already been developed by a select group of partners, including an Android application and augmented reality features with Layar.
Despite growing competition from early mover Gowalla and major players like Facebook and Google, Foursquare remains a dominant platform for mobile location-sharing and check-ins.