Photo-sharing phenom Instagram is celebrating its one-year anniversary on Android with a fun fact: Nearly half of its members are using the Android application.

Instagram launched its Android application on April 3, 2011, a whole 17 months and 30 million users after the popular app for shooting square, filtered photos first debuted on the iPhone. At the time, the service was also just days away from announcing that it would be purchased by Facebook for about $1 billion in cash and stock.

Today's little reveal suggests that Instagram's Android application has at least 50 million active users. The app's Google Play page, which shows a wide range of 50 million to 100 million installs, seems to support the claim.

"We're working hard to make the app fast and easy to use, and we're dedicated to always bringing you the best Instagram experience possible," Philip McAllister of Instagram's Android team wrote in a celebratory blog post. "So to all of our Instagrammers on Android, thank you for helping to make this community amazing. We're glad you're here."

I'm sure they are. The Android application has helped the service become a force to be reckoned with in social-networking land. Instagram has more than 100 million active users and is incredibly popular with teens and tweens who seem to prefer the simplified social experience over Facebook.