More than 17 billion mobile applications will be downloaded from online stores this year, more than double the number of the mini-programs downloaded last year, research firm Gartner said Wednesday.
Gartner said worldwide mobile application store downloads were forecast to reach 17.7 billion this year, a 117 percent increase from the estimated 8.2 billion downloads in 2010.
Worldwide mobile application store revenue is projected to exceed $15.1 billion this year, up from $5.2 billion this year, Gartner said.
It said the revenue figures include purchases of applications, popularly known as apps, by end users and the advertising revenue generated by the programs for their developers.
Gartner said it expected free downloads to account for 81 percent of total mobile application store downloads in 2011.
By the end of 2014, over 185 billion apps will have been downloaded from mobile applications stores, it said.
The Gartner forecast came just a few days after Apple announced that its App Store had hit 10 billion downloads.
The App Store, which was launched in 2008, offers more than 300,000 free and paid apps for Apple's popular iPhone, iPad and iPod Touch.
The success of Apple's App Store has spawned rivals Blackberry, Google, the developer of the Android mobile operating system, Nokia, and others to launch their own online app stores.
"Application stores have become a highly visible and potentially lucrative part of the smartphone 'ecosystem,' largely due to Apple's App Store," said Stephanie Baghdassarian, research director at Gartner.
Baghdassarian said the "app frenzy" was not just a fad.
"We do not think so," Baghdassarian said in a statement. "We strongly believe there is a sizable opportunity for application stores in the future."
Carolina Milanesi, research vice president at Gartner, said Apple's App Store was expected to retain its lead for the forseeable future.
"We estimate that Apple's App Store drove close to nine application downloads out of 10 in 2010 and will remain the single best-selling store across our forecast period (through 2014), although to a lesser extent, as other stores manage to gain momentum," Milanesi said.
Explore further: Apple owns 99 percent of mobile apps market: Gartner