Google has launched a Google Search app for Windows Phone 7. The first Windows Phone 7 devices in the U.S. became available today.

While, we will no doubt see a flood of apps for the platform rush in, it is smart for Google to get theirs out there immediately, as Windows Phone 7 devices come with Bing as the default search option (via a hard key).

Windows Phone 7 presents Microsoft with a tremendous opportunity to gain some market share for its search engine, depending on how well they sell. Many users will probably not actively seek out Google over Bing. They’ll just use the default. 

You might say that many Google users currently use Google more out of habit than any real preference over Bing. Google hasn’t necessarily given them a reason to stop using it a search engine. Likewise, unless Bing gives users a reason to switch, many are apt to just use Bing from their Windows Phone devices, even if they continue to use Google from the desktop. 

"This initial release of the Google Search app includes several features that help you to search faster – suggestions appear automatically as you type, you can choose to repeat a query from your search history, and your current location is used to provide more relevant results," writes the Google Mobile Team. 

The app is of course free, and is available for all Windows 7 devices and languages. It can be found in the Marketplace. 

Windows Phone 7 devices went on sale in the United States today with models available in AT&T and T-Mobile, stores. Currently available models from AT&T include the Samsung Focus and HTC Surround. The HTC HD7 is available from T-Mobile. AT&T is also taking pre-orders for the LG Quantum.