What is FourSquare?
FourSquare is a free location-based social networking app for smartphones where people can see what is going on around them and find their friends' locations.
How can the app be used?
Users can “check in” to FourSquare when they go somewhere, and the GPS coordinates are recorded. It is like a game of sorts, with the ability to earn points and badges for checking in. If enough points are earned, a user is crowned the “mayor” of an area – until someone else earns more. Some businesses also offer discounts to FourSquare users for checking in at their location.
So its a game...?
If all they are interested in is earning points, users can make their check-ins “off the grid.” But part of FourSquare's functionality is letting friends know where they are, so they can meet up and make plans. For this reason, users who plan to share their check-ins must only friend people on FourSquare that they know and trust.
Who can see when they check-in?
No one except a user's FourSquare friends can see their check-in information. However, FourSquare allows users to automatically post check-ins to Facebook or Twitter, which traditionally have much larger networks that aren't limited to close friends only. Depending on the user's Facebook or Twitter privacy settings, these posts may not even be limited to their network of friends or followers.
FourSquare users can add custom geotagged locations, but it's advisable to do so only for public spaces (and not a private place like a user's home, for example.) Another FourSquare safety tip is to check in to a place when leaving, not arriving.
FourSquare can be a handy app for a teen to have on a mobile phone, but it carries safety risks as well. The key to using FourSquare safely is to limit the friends list to only those with whom your teen would feel comfortable sharing his or her location.