Cloak 'anti-social' app helps you avoid your friends

While most social networks aim to connect people, one new service seeks to join the growing trend of doing the opposite and help you avoid them.

Cloak uses public location data from other social networks, Foursquare and Instagram, to determine the locations of others you know.
Users can choose to receive an alert when certain people are believed to be nearby.
It is the latest in the recent trend of "anti-social", or secretive,