In a post on their blog they also announced that over 5 billion photos have now been shared through Instagram.
What makes this even more exciting is that our deal with Facebook has closed, which means we can now work together to evolve and build a better Instagram for everyone. While our team is making the short move to the Facebook offices, Instagram isn't going anywhere. The Instagram app and its features will stay the same one you know and love, and we'll keep working together to build a better Instagram for everyone.
You can download Instagram from the App Store for free.