A rogue application which claims to allow you to see who has viewed your Facebook profile is spreading between accounts on the popular social network. Messages claiming that Facebook has issued a new update which allows you to check who has visited your profile are making the rounds. You should always be very careful, of course, about allowing applications to read and write to your profile. Because at first you may believe that the application is showing you the details of people who have viewed your profile but behind the scenes, it is posting a message to your Facebook account.”]
Source: https://grahamcluley.com/facebook-profile-viewer-rogue-application/