Geo-social networks are location-based social media applications that use GPS or other location methods to identify where a user is located and share that information with friends or communities. Users can check-in to different locations using their mobile phones or devices. This allows friends to see where each other have been, like parks, bars, or restaurants. Popular geo-social networks include Foursquare, Gowalla, Facebook Places, and others. These applications aim to reward users for exploring locations in their cities with badges, coupons, or other perks through a game-like experience.