Photo-sharing service Instagram reached 100 million monthly active users in the first quarter of 2013, says Facebook.
Instagram was launched in October 2010 by co-founders Kevin Systrom and Mike Krieger. When Facebook acquired the app in April 2012, Instagram had around 30 million registered users on iOS, and a billion or so photos.
Mark Zuckerberg, founder and CEO of Facebook, had said back then that Facebook was committed to building and growing Instagram independently.