What just happened? In a move that doesn't come as a total surprise, Facebook has removed its controversial Onavo VPN app from the Google Play Store.

Facebook acquired Israeli analytics startup Onavo in 2013 for between $100 million - $200 million. The Onavo app was advertised as a secure VPN that limited the amount of data background applications consumed, but it was also used for information gathering purposes.

Facebook used Onavo to see how much time people spent in and the amount of data they used on other apps. It also showed their social networks, the country they were in, and even the model of the device they were using.

According to BuzzFeed, the Onavo app revealed to Facebook just how fast Messenger rival WhatsApp was growing, thereby prompting the social network's $19 billion purchase of the company.

Last August, Facebook pulled the iOS version of Onavo from the App Store after Apple raised privacy concerns, though it wasn't removed from the Play Store. But its code was reportedly used in the Facebook Research app, which paid users to access their data. The market research program took advantage of Apple's enterprise certificates, which are meant for employee-only apps. For violating the company's rules, Apple temporarily revoked Facebook's (and Google's) enterprise certificates, blocking the firms from distributing their internal-only iOS apps on the companies' networks.

In addition to removing the Onavo app, TechCrunch writes that Facebook isn't recruiting any more Research testers, but existing studies will continue running.