Instagram is one of the world's largest mobile-photography and video social network. The company was started in October 2010 and has quickly grown over the years. In April 2012, Facebook bought Instagram for over $1 billion. There are now over 200 million monthly active users and an average of 60 million photos uploaded per day. Instagram launched an official app for Windows Phone in late 2013.
It wasn't until November 2013 that Instagram launched an official, albeit beta, app for Windows Phone. Before that users relied on unofficial apps to post pictures to Instagram. Instance and 6tag were the two most popular apps to use Instagram before the official app came out.
The official Instagram app on Windows Phone is still in beta and hasn't been updated since March 2014.