Kevin Systrom had a marketing job at Nextstop. Even without prior knowledge or skill, he learnt how to program simple engineering ideas. One of his ideas led to combine the 'Check-in' ability of foursquare (which allows you to 'check-in' to a location on the map) with the elements of the popular game - Mafia Wars. He made a prototype and named it as 'Burbn'.
Luck was on his side when he met two prominent individuals from Baseline Ventures and Andreessen Horowitz who were immensely impressed with his ideas and decided to fund his venture with $500,000.
As Mike Krieger joined Kevin, Burbn was almost coded into a neat HTML5 mobile app which allowed users to check into locations, make plans (future check -ins), earn points for hanging out with friends, post pictures and much more. However, Burbn seemed too cluttered as an iPhone app, overrun with features.
This led to a shift in focus as Mike and Kevin identified mobile photos as a worthwhile opportunity. An app was built, right from scratch - basically cutting everything from Burbn except its photo posting ability, comments and like capabilities. What remained was Instagram - a photo sharing application and a social-network.
A 1 MB application that allows users to post photos and share with other users - Instagram has more than 100 million users and 1 billion photos on its database today. As homage to both the Kodak Instamatic and Polaroid cameras, Instagram confines photos in a shape of a square. Each second, a new user is added and on an average, 58 photos are uploaded. In its largest acquisition deal to date, Facebook Inc. purchased Instagram for $1 Billion in cash and stock but decided to keep it independently managed. Instagram is available as a free app in App Store and Google Play.