Google Search is plainer on Windows Phone 7 than we'd expect.

It wouldn't be a mobile platform if it didn't have a dedicated Google search app, and this week the Big G ratified Windows Phone 7's competitive existence with a search app of its own--Google Search for Windows Phone 7.

Like others, Google Search uses the phone's GPS to localize searches (on the Samsung Focus, in this case). It hands out search suggestions as you type, but only if you type slowly, we found. It also keeps track of your previous searches, a boon for anyone hoping to bypass typing and repeat a search. Results appear in a browser window, which provides access to image, local, and news results as well as the Web findings.

And that's about it. While suggestions and history are nice additions, were hoping for more than a Web shortcut from the Sovereign of Search in its debut Windows Phone app.

On the other hand, Bing's more polished app enables voice search and spell check in addition to search suggestions. Bing's results look more striking as well, since they manifest in an app and not in a browser search results page--just as we expect for an integrated search incumbent. Image results and search history are missing' however, Bing's local results for "bagel" were mapped in an image and spot on.

Of course, Bing has its interesting splash screen that changes pictures daily, but we have to admit that the app is thinner on features than Bing is on other mobile platforms, like Android and iPhone's iOS. Those Bing manifestations include quick-search options for images, movies, maps, local, news, and directions from that photo-tastic search screen. While Bing offers a richer, more engaging user experience on Windows Phone than Google Search, the lack of all its mobile features is perplexing.

Google and Microsoft compete on Windows Phone 7 on two counts. Not only does the Windows Phone 7 platform take aim at Google's powerful and popular Android operating system, Windows Phones also use Bing as its default search client. For example, pressing the search button (magnifying glass icon) runs your term through Bing. Pinning the Google Search app to the Windows Phone start screen would combat that.

From a business perspective, such a move channels search revenue to Google on Microsoft phones and away from Microsoft, just as the opposite is true for Bing users on Android phones.