Less than three years after it opened for business, the App Store hit the half-million mark



Click to enlarge. Source: 148Apps, Chomp and Chillingo

Here’s a nice round number likely to be trotted out at the Apple’s AAPL Worldwide Developers Conference in June.

Sometime after midnight Tuesday morning,  the iTunes team pushed through a batch of app submissions that sent the total over a six-figure milestone. In 34 months, Apple has approved more than 500,000 iPhone, iPad and iPod touch apps for the company’s U.S. store. (Through attrition, replacement and withdrawal, number of apps currently available for download is 20% lower, around 400,000.)

To celebrate the event, three app-related companies — mobile app blog 148apps, search company Chomp and game developer Chillingo — have issued a jumbo-sized infographic, a portion of which is reproduced above. The fact-packed poster includes a timeline, loads of factoids and a best-seller list topped by Angry Birds, which spent 275 days in the No. 1 spot.

As of January, more than 10 billion apps had been downloaded from Apple’s App Store. Its closest competitor, the Google GOOG Android Marketplace, launched 8 months later, currently boasts 294,000 apps and 3 billion app downloads.

Below: The infographic, chopped up into screen-sized chunks. You can see the 500K Apps banner in its full glory at its Facebook fan page: http://www.facebook.com/500kapps.