Mobile app downloads skyrocketed during the week between tmas New Year’s Day, totaling 1.2 billion cumulative downloads from the iOS App Store Android et, a mobile analytics firm estimates. This was the first time in iOS 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 advertising firm Flurry.

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

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

App downloads from countries such as South Korea pan, where tmas 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 Android devices.” Flurry software is included on more than 20 percent of all applications downloaded from the iOS App Store Android et on any given day, according to the company.

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