WhatsApp is a cross-platform messaging application for mobile devices.

Messages sent via the app are all encrypted. An internet connection is needed, either via mobile data or a Wi-Fi signal.

WhatsApp is currently used by over one billion people worldwide, making it most used messaging app.

It runs on pretty much all devices, including Android, BlackBerry, iOS, Symbian, Nokia and Windows, and it is available in several languages.

The application has been written in Erlang.

Who bought WhatsApp?

WhatsApp was founded in 2009 by former Yahoo! Employees Brian Acton and Jan Koum.

The app was launched in January 2010 and quickly reached the top 20 of all apps downloaded from Apple’s US App Store.

In February 2013, the application had 200 million users, and by December that year it shoot up to 400 million.

In 2014, Facebook spent $19bn to acquire the company which had only 55 employees and nearly 500 million users.

As of February 2016, WhatsApp is used by over one billion people.