WhatsApp is actually a necessity now, it ha completely changed the way we use to chat, earlier we get our cell phones recharged with message pack and use to SMS aur friends and family, but now we get our cell phones recharged with net pack and install WhatsApp and chat online with our friends and family.
There are many online chatting apps available in app store but WhatsApp is a platform where almost all of your friends and family are available . I just love using WhatsApp.