Last week Microsoft updated the YouTube app for Windows Phone, and the application apparently made Google so upset that the company wrote to Microsoft to immediately remove the YouTube app from Windows Phone Store, and close access to the download starting from May 22nd. Factor that makes Google disappointed was the absence of its ads in the YouTube app, it violated YouTube API terms and conditions.
Of course they were less advantaged by the removal, so that they work together to create a Youtube app for Windows Phone. According to The Next Web, Google and Microsoft issued a joint statement stating that they are working together to update the Youtube app for Windows Phone to be acceptable by the terms and conditions of the YouTube API, including the advertisements, a few weeks ago. If the new application has been released, the Youtube application created by Microsoft will be removed from Windows Phone Store.