Instagram is a free photo sharing application that allows users to take a photo, apply a digital filter, then share it on a variety of social networking services including Instagram's own. A distinctive feature confines photos into a square shape, in homage to both the Kodak Instamatic and Polaroid cameras. This contrasts with the 4:3 aspect ratio more typically used by mobile device cameras.
Instagram is compatible with any iPhone, iPad or iPod Touch running iOS 3.1.2 or above. It is distributed via the Apple App Store. An Android version has been announced though no release date has yet been confirmed.