I definitely would've thought this would mainly be used for porn, but the internet is full of surprises...
The magical app in question is called FakeApp, it's a program that uses an impressive algorithm to scan a person's (such as a celebrity's) face and edit it into other videos. What's the perfect use for said app? Apparently, it's to edit the face of beloved actor Nicholas Cage into damn near anything you can think of. James Bong? Cage. Indiana Jones? Cage. Lois Lane? Cage.
It's an amazing time to live in.