Facebook owns the world’s most popular app WhatsApp, which it bought for $19 billion in 2014, hit a major milestone on Thursday. WhatsApp founder Jan Koum said the service now has 900 million monthly active users worldwide.
Monthly active users isn’t the best way to measure activity on a messaging app. WhatsApp did not say how many messages are being sent each day, for example. But the growth is impressive. WhatsApp announced it had crossed 800 million in April. That is no small feat for either app: Smartphone owners spend more time in messaging apps than any other app.
Messenger is also surging in popularity. It’s now the second-most popular app in the U.S, surpassing Google-owned YouTube, according to a com Score report.
By way of comparison: Twitter has a bit more than 300 million monthly active users. Instagram, the photo and video sharing app owned by Facebook, also has about 300 million.