Instagram has passed yet another milestone on its path to dominating the mobile photo-sharing space. Less than one year after launching, Instagram now has more than 10 million registered users.

That’s more than double the number of users Instagram had in mid-June and around 3 million more users than it had at the beginning of August (at which point there were 150 million photos on the service).

Impressively, Instagram has been able to attract such a large number of users despite the fact it is only available on one platform — iOS. The iPhone app received a big update last week when version 2.0 of Instagram was rolled out. Although Instagram is not yet available on Android, Instagram CEO Kevin Systrom says developing a version of the app for that platform is a priority.