Instagram has long been a favorite app of Apple iOS users, but all that time that the popular photo-sharing application spent growing a solid foundation of iPhone-using photographers, consumers that were using Android-based smartphones were stuck using crappy knock-offs such as RetroCamera and Vignette.

Thanks to a concerted effort from its developers, Instagram has finally been released for the Android operating system -- and it's quickly become one of the must-have apps for photographers.

Instagram for Android, released Tuesday on Google Play (formerly the Android Market), has been a runaway success, racking up more than 1 million downloads in less than 24-hours. Instagram CEO Kevin Systrom told the New York Times that the company was signing up more than 2,000 people a minute.

Access to the Android user base -- more than 300 million activated smartphones -- could be a significant boost for Instagram. Prior to its release on Android, the application had 30 million users uploading more than five million photos each day according to a NYTimes article.

Instagram for Android was first unveiled at the South By Southwest Conference in Austin, Texas last month. Registration for the app began on March 25, snagging 430,000 emails, but the app wasn't officially released until this week. As one of the most popular mobile-phone-only social networks, it will be interesting to see how Instagram matures now that it's tapped into one of the largest user bases in the world.

In a report published by comScore today, Android was shown having finally snagged more than half of the smartphone market. The report states that 50.1 percent of the U.S. smartphone subscribers 13-years-old and above are using Google's Android OS..

In a distant second was Apple iOS with 46.9 percent. Google's Android OS increased market dominance by 3.2 percent year-over-year, wheras Apple only grew 1.5 percent. The year-over-year growth, not to mention the market dominance, of the Android operating system will undoubtedly work in Instagram's favor. Needless to say, 1 million downloads in 24 hours is just the tip of the iceburg for this blossoming company.

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