Instagram is a free photo-sharing program and social network that was launched in October 2010. The service enables users to take a photo, apply a digital filter to it, and then share it with other Instagram users they are connected to on the social network as well as on a variety of social networking services.[3] As of September 2012, Instagram had 100 million registered users.[4] 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.