WhatsApp surpassed Facebook to become the most popular Facebook-owned app, which recorded a 30% growth in the past 24 months. WhatsApp Messenger app crossed Facebook in terms of monthly active users in September 2018, as per App Annie's The State of Mobile 2019 report.
Instagram, which is also owned by Facebook recorded a strong 35% growth globally from January 2017 to December 2018. Facebook and Facebook Messenger grew 20% in and 15% in the last 24 months respectively.
The report notes that the total time spent on Social and Communication category apps in 2018 increased 35% from 2016. This suggests an increase in the importance of mobile phones. The emphasis seems to be on videos given the popularity of apps like Instagram, Snapchat and Tik Tok.
WhatsApp Messenger was the top Social and Communication apps when it comes to per-user engagement in 2018 in most countries including India, Brazil, UK, Germany, and Canada. This was measured by average monthly sessions per user.
In India, WhatsApp Messenger was followed by Instagram on the second position and Facebook on the third. The fourth and fifth most popular Social and Communication apps in the country were Facebook Messenger and imo respectively. Snapchat took the top spot in the US.
The decline in Facebook's popularity worldwide can be attributed to a series of privacy issues concerning data of users on the platform. The social media giant is under heat in many countries for security-related issues and how its management handled the Cambridge Analytica data scandal.
Meanwhile, WhatsApp is end-to-end encrypted and the service benefits from "a simple users interface, ease of use to add contacts and interest in encrypted messaging," the report notes. Then there is free calls and messages that have helped WhatsApp grow immensely.