Within a year after launching its Android app, nearly half of all Instagram's user base comes from the Google-powered operating system.

Instagram revealed this statistic in a blog post celebrating its one-year anniversary Wednesday. The popular photo-filtering and -sharing app currently has 100 million monthly active users.

"Instagram for Android has helped make this community more global than ever," said Philip McAllister, an Instagram engineer. "Major events such as Brazil’s Círio de Nazaré festival, the 85th birthday of Thailand’s King Bhumibol, and a streak of severe thunderstorms throughout Malaysia have been captured by Android Instagrammers and shared to global audiences like never before."

Co-founder Kevin Systrom unveiled Instagram's long-awaited Android app at last year's South By Southwest. The app, which officially debuted on April 3, 2012, saw over a million downloads in less than a day.

Instagram for Android runs on any camera phone with Android versions 2.2 (Froyo) or above that support OpenGL ES 2. It is available for free download in the Google Play store.

For its part, Instagram's iPhone app hit the App Store in 2010 after co-founders Systrom and Mike Krieger launched the service.

Are you surprised that half of all Instagrammers are Android users? Why or why not? Tell us in the comments, below.

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Image courtesy of Instagram