Confused? Well we are not talking about the Tango update here. Tango is a multi-platform app that allows you to make free phone calls and free video calls over 3G, WiFi or LTE networks. Tango is now available fow Windows Phone Mango devices. It is the first app that enables video calling on WP7 devices.
The good thing is that it is available for Android, iOS, Windows and Mac so you can make video calls to any platform free of cost.