It is an online photo-sharing and social networking service that enables its users to take pictures, apply digital filters to them, and share them on a variety of social networking services, such as Facebook or Twitter. A distinctive feature is that it confines photos to a square shape, similar to Kodak Instamatic and Polaroid images, in contrast to the 16:9 aspect ratio now typically used by mobile device cameras.
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.
Instagram is distributed through the Apple App Store and Google Play. Support was originally available for only the iPhone, iPad, and iPod Touch; in April 2012, support was added for Android camera phones running 2.2 Froyo.