Google has released its first Windows Phone 7 app: Google Search. The application currently allows you to search in four sections: web, images, local, and news. It also features auto-suggestions (but not Google Instant) and uses your current location to provide more relevant results.

The search giant released its free app yesterday, the same day Microsoft launched Windows Phone in the US. Windows Phone 7 ships with Bing integrated as part of the mobile OS but Google is offering an alternative to that experience. The application is available now in the marketplace, and while it's not as integrated into the mobile OS as Bing is, nobody can argue with having the option to use alternatives.

Google also recently updated its mobile website to include Google Instant, which displays search results as you type. The feature was released for desktop browsers two months ago, and Mountain View then said it was planning to port the feature to mobile platforms.

You may think the feature would be slow on mobile browsers but Google says a new AJAX and HTML5 implementation dynamically updates the page with new results without the need to load a new page for each query. The feature is still in beta and must be enabled by hitting the Google Instant "Turn on" link beneath the search box on Google.com.

Google Instant for mobile is currently only available on Android 2.2 (codename Froyo) devices and iPhones and iPods running iOS 4 in the US, in English. Google says this is "most iPhone and Android devices in the US," which is inaccurate since most users don't have the latest version of Android or iOS. In any case, the company says it's working to support additional countries and languages and more devices in the coming months.