Over 2.1 billion people use Facebook's apps on a daily basis

"Facebook said over 2.1 billion people now use its family of applications—Facebook, Instagram, WhatsApp and Messenger—on a daily basis, and more than 2.7 billion do so on a monthly basis.
Facebook reported an average of 1.59 billion daily active users at the end of the second quarter, up 8% compared with the year-ago period. Wehner said gains in India, Indonesia and the Philippines helped drive growth."

Source:  AdWeek, 26th July 2019