from: http://www.engadget.com/2011/09/04/tango-video-calling-en-route-to-windows-phone-mango/:

Good news, people – Tango is about to get Windows Phone. Not the Tango . We refer to the video calling service which is already very popular on IOS and Android, but there was absolutely no presence on the Microsoft platform at all. Of course, there is a reason quite obvious why: the OS does not support cameras face until the mango has come. The unveiling this week of the first HTC devices WP7.5 , someone browsing software for radar happened through an application of Tango in the Start menu, showing users will have more video chat options to choose from than just Skype. Better yet, it seems to offer cross-platform compatibility so you can see your Android-toting friends and your iPhone with the regulations up close and personal. We are delighted to see the function finally ready to go with the beginnings of Mango, but unfortunately this is a matter of time before the name confusion sets in.