https://www.theverge.com/2019/1/31/18206020/apple-facebook-internal-ios-apps-restores-enterprise-certificate

Facebook said today that Apple has restored its enterprise certificate, the software permission that allows the social network to load internal mobile apps onto the devices of employees, beta testers, and research participants.

The move comes roughly one day after Apple blocked Facebook from using the program after a TechCrunch investigation revealed it had re-skinned its Onavo VPN app, pulled from the App Store last summer, as the “Facebook Research” app. Facebook was paying teenagers and adults $20 a month to use the app, which was not distributed through proper iOS channels and was instead sideloaded using Facebook’s enterprise certificate, to siphon sensitive smartphone data. Facebook pulled the app in response to the backlash, but Apple blocked the company anyway because it was in “clear breach of their agreement with Apple” to use the certificate in such a fasion.