This document summarizes information about Instagram. It discusses that Instagram is a mobile photo sharing application that allows users to share photos and videos publicly or privately. It was founded in October 2010 by Kevin Systrom and Mike Krieger. Some key facts provided are that Instagram reached 5 million users in 9 months and 150 million photos, faster growth than Flickr. The document also discusses why Instagram became so popular, noting its ease of use on mobile devices, photo filters, and social sharing features like likes and comments similar to Facebook. Finally, some common reasons people use Instagram are to document daily life, connect with others worldwide through hashtags, get likes on photos, be creative with filters, and for fun and addiction to the platform.