Foursquare is a free app and social networking site that allows you to keep record of places you’ve visited.
Why should I use Foursquare?
2. Foursquare uses GPS to show you what is nearby — it’s helpful when you’re looking for a place to eat or shop.
3. Some businesses offer coupons and special deals for checking in.
4. It’s a game/competition, too. You could become “mayor” of a location, such as a truck stop, by checking in there more times than the current mayor (if there is one).