The App Store That's Never Closed GetJar has quietly emerged as the mobile app portal of choice for millions worldwide.

It's a point that's hammered home time and again via Apple's ubiquitous marketing campaign: Whatever the situation, no matter how commonplace or unusual, there's an app for that. Since launching its App Store mobile application marketplace in mid-2008, Apple and its global network of software partners have introduced more than 100,000 apps for the computing giant's iPhone and iPod touch devices, translating to developer revenues topping $900 million. Data issued in late 2009 by mobile advertising firms Millennial Media and Mobclix indicate that consumers are now downloading in excess of 100 million free and premium applications from the App Store each month, arming their iPhones with the latest in navigation tools, friend finders, utilities and games.

Although there may be an app for iPhone users wherever they are and whatever they're doing, many of those apps are exclusive to the iPhone platform, even though Apple controls only 17 percent of the worldwide smartphone market, according to research firm Gartner. Despite declining global sales, Finnish titan Nokia still owns close to 40 percent of the smartphone market, followed by Research In Motion (the Canadian manufacturer behind the BlackBerry device portfolio) at 21 percent. Like Apple, Nokia and RIM now oversee their own application storefronts--Ovi Store and BlackBerry App World, respectively--and because each company's devices run on rival operating systems, software downloaded from Apple's store won't work on a Nokia smartphone, or vice versa. Add in competing operating systems such as Google's Android and Microsoft's Windows Mobile (each with its own proprietary application store as well), and the big picture becomes as fragmented as a jigsaw puzzle where none of the pieces quite fit together.