Apple Has Most Apps, But Rivals Catching Up

According to the report, Apple's fastest-growing app category was business, which surprised many, based on the company's reputation for media and entertainment. Android Market had the highest growth rate, reaching 130,000 apps by the end of 2010, or more than six times the number from a year ago, while Nokia's free apps surged to 25,000, more than triple its size within the year.

Meanwhile, BlackBerry's online store also hit 18,000 apps from an especially strong boost in games and other entertainment features.

The results reflect the shifting dynamics of app development in the increasingly-lucrative mobile market. While the volume of games in the iTunes App Store reflects the popularity of the iPhone, Apple has developed a closed ecosystem that requires programmers to accept the most stringent of policies.

By contrast, Nokia, Android and RIM have courted software developers with instructional events and new tools in an effort to catch up to Apple. They also sometimes offer a different profit share structure than Apple, which may appeal to some programmers.

"The high download volumes of free applications appear to attract developers to switch to monetization methods other than paid," said Hendrik Koekkoek, an analyst at Distimo.

Apple may win in the numbers department in the budding app store battles, but its rivals are determined to compete, especially as app usage ramps up.