Foursquare 4.0 for iOS 5 Adds Radar Feature
Foursquare today announced a major overhaul of its iOS application for devices running iOS 5. The new version of Foursquare adds a new feature called Radar, which automatically sends alerts to the device when it sees that events are taking place near the user, or if the user's friends do something close by. The free update also adds some minor tweaks for devices running iOS 4, including new sharing features. The update is available from iTunes.