Whatsapp is the famous social app used to communicate with the persons present in your contacts and they also using this app. You just need an internet connection for this app to use.
With this app you can send free messages, images, recordings, videos, audios, pdf files, contacts and location for free.
Earlier you have to pay for yearly but now its free for lifetime. You can set your DP(Display pictures) or profile pics and write the status about your current mood.
If you wan to talk with many peoples at the same time than you can create the group and add them in it other way to conduct the same message to all is through by the broadcasting.
You can set your privacy settings according to your’s wish.
Great app to be social with friends and family.
You can call through this app also to whom you want nut he/she is also using the whatsapp.
No charges for calling just require an internet.