Today, WhatsApp is the single most-used independent smartphone app in nearly every country in the world. It has hundreds of millions of users and sends as many as 18 billion messages per day. And, as CEO Jan Koum said onstage at D:Dive Into Mobile Tuesday, WhatsApp is now bigger than Twitter, which officially claims 200 million monthly active users. The company daily processes 8 billion inbound messages and 12 billion outbound.
The app has repeatedly been rumored for acquisition but has denied those rumors. It plans to move to yearly subscription model for iOS users later this year.