https://techcrunch.com/2020/02/12/whatsapp-hits-2-billion-users-up-from-1-5-billion-2-years-ago/

WhatsApp, the most popular messaging app, revealed today just how big it has become. The Facebook-owned app said it has amassed two billion users, up from 1.5 billion it revealed two years ago.

The announcement today makes WhatsApp the only second app from Facebook to join the two-billion-users club. (Facebook’s marquee app has 2.5 billion users.) In an earnings call late January, Facebook also noted that that there were 2.26 billion users that opened either Facebook, Messenger, Instagram, or WhatsApp each day, up from 2.2 billion last quarter. The family of apps sees 2.89 billion total monthly users, up 9% year-over-year.