WhatsApp, a mobile messaging platform, is a cross-platform app which allows users to exchange messages without having to pay for SMS. WhatsApp Messenger is available for iPhone, Blackberry, Android, Windows Phone, Nokia, and Symbian platforms. Founded by Brian Acton and Jan Koum in San Francisco in 2009, WhatsApp's venture investor was Sequoia Capital and the company was acquired by Facebook in 2014.
Since WhatsApp Messenger uses the same internet data plan that subscribers use for email and web browsing, there is no cost to message and allows them to stay in touch with their friends.
In addition to basic messaging WhatsApp users can create groups, send each other unlimited images, video, and audio media messages.