It hasn't taken long for Instagram to catch on. Just seven months after its launch, the iPhone photo sharing app has reached 4.25 million users.
The news comes by way of a tweet by the New York Times' Nick Bilton after he said he chatted with Instagram CEO and co-founder Kevin Systrom over coffee. Instagram has maintained an impressive growth rate.
It was in the App Store for just three months before it hit themillion user mark, and just six weeks later, it had doubled that number, adding an additional million Instagrammers.
Launched in October, Instagram is an app that lets users add 11 different custom filters to photos in order to change the colors, mood, border, and tonality of their snapshots. It was arguably one of the break-out apps of SXSWi back in March, although it hasn't yet launched an Android version.
To put Instagram's growth into perspective, Twitter didn't reach a million users for two years. Officially Twitter now has more than 200 million registered accounts, though some suspect that number is closer to 300 million. But it took a while for Twitter's growth to pick up; Twitter was founded in 2006, but one study has said 95 percent of accounts were created in the last two years.
In terms of numbers, Instagram could soon surpass Foursquare. Launched in March of 2009, Foursquare now has about six million users, and it took it about a year to snag a million users.
While there are plenty of photo-taking apps out there, Instagram seems to be one of the current front-runners for iOS users.