Founded in 2009 by Brian Acton and Jan Koum, WhatsApp is a cross-platform instant messaging app that allows you to send messages without having to pay for SMS. It can be used to send text messages, video, images and audio media messages.

In February 2014, Facebook acquired WhatsApp. By April 2014, WhatsApp reached half-a-billion active users worldwide.

As of June 2014, the client software for WhatsApp was available for iOS, Android, Windows Phone, BlackBerry OS and select Nokia and Symbian mobile operating systems.