Google’s app in question does pretty much the same thing as the Facebook Research VPN. Even the manner in which is it installed is near identical – the company gets users over the age of 18 to download the app via a special code and its enterprise certificate.
In a statement to TechCrunch, Google said: “The Screenwise Meter iOS app should never have operated under Apple’s developer enterprise program – this was a mistake, and we apologize. We have disabled this app on iOS devices.” The immediate result of this was the revoking of enterprise certificates which also crippled its employee-only apps. Their functionality has since been restored, alongside the company’s enterprise certs. (Source: TechCrunch [1], [2])