What is Instagram?

Instagram is a photo sharing application that lets users take a photo, apply a digital filter, and distribute them to various social networking services, including Instagram's own.

What is Instagram? (news.cnet.com)

One unique feature in Instagram is cut into a square image, so it looks like the camera Kodak Instamatic and Polaroid. This is different from the 4:3 aspect ratio that is commonly used by cameras on mobile equipment.

Instagram can be used in the iPhone, iPad or iPod Touch with any version of the operating system IOS 3.1.2 or later and any Android camera phone with operating system 2.2 (Froyo) or later. This application is spread through the Apple App Store and Google Play.

On 9 April 2012, it was announced that Facebook agreed to take over Instagram with a value of approximately $ 1 billion. (wikipedia)