The Windows Phone Marketplace app store for owners of Windows Phone-based devices continues to gain more and more apps for its users. Today the third party web site All About Windows Phone reports that, according to its calculations, the number of apps that have been published on the Windows Phone Marketplace has now exceeded the 45,000 mark.

The site claims that at the time of their news post, 45,610 apps have been published in the Windows Phone Marketplace. Of that number, 14,261 apps were added in the last 90 days and 5,837 app were added in the last 30 days. These numbers seem to show that the number of apps that are being made available to Windows Phone users is accelerating.

If the current trends continue, the Windows Phone Marketplace could reach the 50,000 app mark sometime in early January 2012, although it's possible that the app store could reach that milestone number before the end of 2011.

Even though the number of applications for Windows Phone users is increasing, it still has a long way to go to reach the numbers available to owners of iOS and Android-based devices. Today Apple announced that over 500,000 apps are now available to download for iPhone, iPad and iPhone Touch users.