I remember those days when we have text messages fot chatting and we have to spend so much money for message pack and then also we used to get limited 500, 1000 messages.but after coming of whatsapp life becomes easy , you just need a internet pack and need to dowload this app.you can send unlimited texts and recieved so immediately.not only texts you can send pictures, videos, voice message, songs and so much things in just single app.you whatsapp get automatically updated according to your contact list.you dont have to add or do anything.there are lot of other features also like you can put your profile picture and status and see others also.you can see others last seen and when they are online.you can put chat wallpapers.you can block someone whom you dont know or dont like.you can makr friends group .features are just uncountable.when your day passes with it you dont even realise.its a great app.