The Instagram Android app has acquired over 500 million installs, a milestone that only a few items in the Play Store can claim. The majority of them come from Google, but Instagram marks the third one from Facebook.
Aside from Google and Facebook, only two other companies have made it into this exclusive club, with one gaining access on a technicality. Microsoft is in, thanks to Skype. The other is Samsung, whose Push Service has managed this many installs with most users not even aware that it exists, let alone actively searching for it in the Play Store.
Clearly Facebook's presence has not discouraged users from flocking to Instagram in the years since the acquisition. We'll have to wait and see if the service's growth slows down any time soon.