Facebook has begun rolling out a "Protecting Your Information" News Feed notification to let people know whether third party applications shared their Facebook data with analytics firm Cambridge Analytica.
Facebook created this tool that will let you know if you or any of your friends logged into the "This Is Your Digital Life" app, which ultimately shared data with Cambridge Analytica. here is the link.
If you’re one of the 87 million users who had a friend that logged into the app, it will look like this: