Read more at itnews.com.au
Apple has strict rules regarding the distribution of apps on it's platforms. Developers have to submit their apps to Apple for review before they can be made available on the official App Store. It allows direct installation of software from outside its App Store only for enterprise developers and that too is very rare.
Facebook gets around these restrictions with a top-level root enterprise certificate for the app. This allows installation of the app from outside the App Store.
The current version of Onavo Protect has been renamed as PowerLogs.app. The app could capture a large amount of user data, including private messages on social networks and encrypted data.
Facebook declined to comment on its use of the enterprise certificate or how many people have downloaded this app, but said they have been transparent about the app's purpose.