Whats app is the one of the best social network ever. I have been using this from last 5 years. It is very secured social network in the world. Initially all people were using Facebook this Whats app came as social network. As per my knowledge Whats app users are more than Facebook. The features of this is very use full. We can do group chat at a time with lot of people. And recently it introduced video call also. The very good social network.