Apple temporarily banned Facebook and Google from running internal software, sending a strong message. Facebook created Facebook Research App a volunteer program that functioned as a VPN when installing on phones. Volunteers had to choose to install the app, and received $20 a month in e-gift cards. Facebook has since shut down Facebook Research on iOS, but it still has a similar app on Android. Google also shut down Googles internal iOS apps, citing the same violation of policies.”]
Source: https://hackercombat.com/did-apple-really-ban-facebook-and-googles-apps-why/