Microsoft (NSDQ: MSFT) is now providing its application marketplace to older Windows Mobile devices and is promising that 90 percent of the 800 applications in the catalog \will be compatible. The Windows Marketplace for Mobile launched on Windows Mobile 6.5 just about a month ago, and now it will work on Windows 6.0 and 6.1, which make up about 30 million devices worldwide.

Microsoft is playing catch-up in the application storefront business, and is making big strides over the past month, including the announcement last week that the app store is now available online from the PC. To increase awareness of the marketplace, Microsoft said in a blog post that it will advertise the downloadable storefront online. “We may not have built the first application store, but we did set out to pioneer a fresh Marketplace experience that we look forward to expanding upon in the months and years ahead,” wrote Microsoft’s Eric Nelson.