Geolocation services and apps allow users to check-in and share their locations. Some popular examples mentioned are Foursquare, Google Latitude, Yelp, and TripAdvisor. Foursquare allows users to check-in to venues, earn badges, see who the mayor is of a location, and leave tips. It has features for friends, exploring places, lists, and statistics. The app is available on Android and other platforms also have simple check-in options. Some recommend using badges, avoiding fake check-ins, and using tools to analyze Foursquare data.