Mobile app downloads skyrocketed during the week between Christmas and New Year's Day, totaling 1.2 billion cumulative downloads from the iOS App Store and Android Market, a mobile analytics firm estimates. This was the first time in iOS and Android history that more than one billion applications were downloaded worldwide in a single week. The bulk of those billion plus downloads originated in the United States, accounting for 509 million downloads or 42.3 percent of the total, according to mobile analytics and advertising firm Flurry.

The weeklong lull between Christmas and New Year's is typically seen as a big week for app developers, thanks to the large spike in newly gifted iOS and Android devices. Flurry said total activations of iOS and Android devices topped 6.8 million on Christmas Day and reached more than 20 million activations during the last week of 2011.

The 2011 Christmas bump was apparent in Flurry's numbers as all but one of the top five app downloading countries for the week were Christmas-celebrating nations. In addition to the U.S., the U.K., Canada and Germany also broke into the top five for Christmas week. The lone non-Christmas celebrating standout China, which was second with 99 million downloads during Flurry's so-called "power week." China is the world's most populous nation and has a booming smartphone market.

App downloads from countries such as South Korea and Japan, where Christmas is not celebrated by the majority of people, placed lower during the week than is typical, according to Flurry.

Flurry based its estimate on more than 140,000 third-party apps that use Flurry analytics running on what the company says is a "significant majority of iOS and Android devices." Flurry software is included on more than 20 percent of all applications downloaded from the iOS App Store and Android Market on any given day, according to the company.

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