Fingerface - FaceID backward allows you to use your face to authenticate app usage. Although there's an option for fingerprint authentication, this was no longer possible due to the removal of said function in Pixel 4. Hence, Semon created this app for authenticating apps that require the use of fingerprints. 

Thankfully, Fingerface - FaceID backward doesn't require expert-level technical skills. You only need to tap “Confirm” and you can now access fingerprint-authenticated apps. Bear in mind that Fingerface - FaceID backward requires Xposed to work. If you don't Xposed, this tool will not work.