Downloads of Instagram’s Android application continue to grow at an impressive rate, today hitting 10 million downloads on the Google Play Marketplace, just 22 days after it launched on the platform.

Instagram is enjoying a relatively quiet period after the buzz of its Android launch, then the unexpected and huge announcement that it had been bought by Facebook for $1 billion. The company is looking at hitting 50 million users on all platforms after reaching the 40 million mark just under two weeks ago.

If you’re unaware of Instagram’s successful Android launch, it started with the app reaching 1 million downloads in under 24 hours. It then only took another five days for the company to add another four million downloads, surpassing the 5 million mark on its sixth day of availability.

Today it has doubled that tally, taking a little over two weeks to do so:

Screen Shot 2012 04 25 at 10.16.49 520x202 Instagram for Android hits 10m downloads in 22 days, as the service nears 50m total users

Android users had been waiting a long time for the photo-sharing app to launch on the platform, and even when the company launched its pre-registration process, Android smartphone owners rushed to be a part of it. When it opened pre-registration for its Android variant on March 24, it attracted 430,000 pre-registration signups in the following days.

Instagram currently has more than 47 million users (not all are active), with it certain to reach the 50 million milestone in the coming days.

With news of the acquisition hitting media outlets and news channels the world over, more and more users are becoming aware of the service and seeing friends and family interact and share photos using the app to Facebook and Twitter, helping it move into the mainstream.

Facebook may have paid a hefty price for the popular app, but given its increasing popularity and huge usage, it is looking to be a very smart buy by Zuckerberg and co.