What is whatsapp?

[The Legenday Hart]

My friend just asked me if I use it, but I have no idea what it is?

[Leon]

it's a messenger that connects with people. Like facebook messenger or kik.
its just texting

[Ankit]

WhatsApp Messenger is a proprietary, cross-platform instant messaging subscription servicefor smartphones. In addition to text messaging, users can send each other images, video, and audio media messages as well as their location using integrated mapping features. The client software is available for Google Android, BlackBerry OS, Apple iOS, selected Nokia Series 40, Symbian, selected Nokia Asha platform, Microsoft Windows Phoneand BlackBerry 10.

[Jim]

It's the #1 messaging app in the world and was just bought by Facebook in a deal worth some $19 billion in cash and stock.

[Piyush]

WhatsApp Messenger is a proprietary, cross-platform instant messaging subscription service for smartphones. In addition to text messaging, users can send each other images, video, and audio media messages.

[Jak]

http://techwhatsapp.com/ have many article to let you know what WhatsApp is and how it is helpful.

[i]

Its a free messenger which is used by billions of people that are living on earth and it is the most popular messenger till date. By the way, you posted this question from EARTH right??