https://www.techradar.com/news/facebook-suspends-approval-of-new-third-party-apps

In the wake of the Cambridge Analytica data scandal, Facebook has temporarily suspended approval of new third-party apps. It announced the news on its developer blog, providing an overall update on the measures it's taking "to maintain the trust people place in Facebook".

The data used by Cambridge Analytica was gathered using a personality testing app called thisisyourdigitallife. The app not only collected information about the person who took the test, but also about their friends, who hadn't consented to it. Facebook put an end to that practice in 2014, but Cambridge Analytica kept the data it had gathered and continued to use it to provide targeted advertising.