Instagram is an online mobile photo-sharing, video-sharing and social networking service that enables its users to take pictures and videos, and share them on a variety of social networking platforms, such as Facebook, Twitter, Tumblr andFlickr.^[5] A distinctive feature is that it confines photos to a square shape, similar to Kodak Instamatic and Polaroid images, in contrast to the 4:3 aspect ratio typically used by mobile device cameras. Users can also apply digital filters to their images. The maximum duration for Instagram videos is 15 seconds.^[6]

Instagram was created by Kevin Systrom and Mike Krieger, and launched in October 2010. The service rapidly gained popularity, with over 100 million active users as of April 2012^[7][8] and over 300 million as of December 2014.^[9] Instagram is distributed through the Apple App Store, Google Play, and Windows Phone Store.^[10] Support for the app is available foriPhone, iPad, iPod Touch, and Android handsets, while third-party Instagram apps are available for Blackberry 10 and Nokia-Symbian Devices.^[11][12]

The service was acquired by Facebook in April 2012 for approximately US$1 billion in cash and stock.^[13] In 2013, Instagram grew by 23%, while Facebook, as the parent company, only grew by 3%.^[14]