The concept of the application is great but not very original, not to mention the poor video quality and very buggy connectivity which occasionally results in dropped or lost calls. The user base is very thin but this shouldn’t be a huge issue seeing as you can add any of your personal contacts easily.
Tango isn’t an application I would recommend simply because it isn’t the best of its kind available. Facetime and Skype are just two of many video calling applications that top Tango. Tango lacks text messaging which most others provide and the connection and video quality just isn’t up to par with its competitors. Shop around and try all video chat applications to see which you like best.