I am using whatsapp from 3 year .It is a very nice application which has being purchased by facebok. Since I am using whatsapp from past 3 year I am really impressed with whatsapp. It is very helpful sending messages accross the world. It also offer the video calling chats free of cost. The calling is very nice . the clearity of video calling is also okay.
I would reccomend to all my friends to download the whatsapp application