Instagram is a free social network service built around the act of photo-sharing. Launched in October 2010, Instagram enables registered users to take a picture (using the camera on their mobile device), apply a digital filter to it, and share it across multiple social networks (including its own). Self-described as "allow(ing) you to experience moments in your friends' lives through pictures as they happen," Instagram began as an iOS-only (Apple) application, becoming available on Android devices in April 2012. Along with the digital filters (which Instagram describes as "transform(ing) the image into a memory to keep around forever"), a unique feature is that Instagram confines photos to a square shape, similar to Polaroid images. In April 2012, Instagram was acquired by Facebook for approximately $1 billion in cash and stock, with Facebook stating their plans to keep Instagram independently managed. In late 2012, Instagram rolled out profile pages on the web (similar to a Twitter or Facebook profile page). Users can follow other users, like and comment on photos, as well as edit their profile via the website (instagram.com/username).
Definition in part from Wikipedia, Instagram