Determine Facebook/Instagram referrer
Determines if a webpage visitor comes from Facebook web/app or Instagram web/app
How to test it
Access the suggested post and should be able to see what is described below.
https://www.facebook.com/taltk9/posts/10213069861895165
Facebook card
Instagram [doesn't work for while]
https://www.instagram.com/p/B3Kr6egBkuN/
Instagram card
https://twitter.com/devthiago/status/1179832412538318848
Should be able to see a blank page.