Instagram Hits 40M Users

Instagram signed up 10 million more users—bringing its total to 40 million—in just the past 10 days. The retro-styling, photo-sharing app was the talk of tech after releasing a version for Android and then getting scooped up by Facebook for $1 billion, reports SlashGear. Instagram launched for the iPhone in October 2010, and picked up its first 1 million users in a mere two months. (More Instagram stories.)