As the newest addition to the Facebook family, WhatsApp is one of the superstars in the mobile messaging space.
Today we're having a look under the bonnet of the billion dollar app.
Former Yahoo employees Brian Acton and Jan Koum decided to take a break after work and took a sojourn in South America. After returning and failing to land a position at Facebook, the pair stumbled on the idea of WhatsApp.
The app was first launched in 2009, and five years later Acton and Koum were back at Facebook. This time selling their startup for US$19 billion.
The pair reportedly knocked back an earlier offer from Google for a paltry US$10 billion.
WhatsApp currently has over 700 million monthly users.
To put this in context, LinkedIn has 260 million users, Instagram has 400 million.
WhatsApp is also popular around the globe, with 70 million users in India alone.
Text and talk
WhatsApp users are a chatty bunch. Over 70% use the platform daily, while 1 million new users sign up for the privilege every 24 hours.
The average user spends 195 minutes every week on WhatsApp.
Messages are the most popular way to communicate on the app.
Over a typical day 30 billion messages, 200 million voice messages, 100 million video messages and 700 million photos are sent on WhatsApp.
And WhatsApp users aren't immune to the power of the selfie. The app is responsible for 27% of all selfies shared on social media.