Find my friends
The Apple-style Find My Friends app lets you quickly locate your friends and loved ones using your iPhone, iPad or iPod touch. Install this free app on your iOS 5 device and sign in with your Apple ID for iCloud.
Instagram is a free photo-sharing application that allows users to instantly apply filters and frames to newly taken photos, and share them via Instagram or many other social networks, including Facebook, Twitter, Foursquare, Tumblr, Flickr, VKontakte and Posterous.
The Facebook app allows you to stay connected and share information with your friends on the go.
foursquare
The foursquare platform makes it possible to learn a lot about the city in which you are located, and even arrange a spontaneous meeting with friends.
LinkedIn is a social networking site for finding business contacts with over 120 million registered users from 200 countries representing 150 business industries.
Localmind
Localmind will help you decide where to go and what to do, say, in a new city, and ordinary people who are right now in the same city or area will help you – who, however they may, can give the best advice to a visiting citizen.