Instagram is a photo-sharing social networking site that allows users to filter, transform and share photos from iOS and Android devices. A unique aspect of the service is that images are shared in a square format similar to Instamatic and Polaroid images, an effect often heightened by the available filters.
Instagram was incorporated in late 2010 and reached 100 million users in April 2012. Facebook acquired the company in April 2012 for $1 billion.