WhatsApp Messenger is a proprietary, cross-platform instant messaging application for smartphones. In addition to text messaging, users can send each other images, video, and audio media messages. The client software is available for Android, BlackBerry OS, BlackBerry 10, iOS, Series 40, Symbian (S60), and Windows Phone. WhatsApp Inc. was founded in 2009 by Brian Acton and Jan Koum, both veterans of Yahoo!, and is based in Santa Clara, California.
Competing with a number of Asian-based messaging services (like LINE, KakaoTalk, and WeChat), WhatsApp was handling ten billion messages per day as of August 2012, growing from two billion in April 2012 and one billion the previous October. According to the Financial Times, WhatsApp "has done to SMS on mobile phones what Skype did to international calling on landlines." This service is free for the first year then costs $0.99/Yr..
As of June 20, 2013, WhatsApp has over 250 million active users, and handles 27 billion messages in a single day.
