I can think of two "useful" applications of this tech... 1) see what you look like with cosmetic surgery / tattoo / etc before permanently modifying your body. 2) Try on clothes before shopping online.
But both still don't solve the underlying issue I have with this tech. Even the "useful" ideas for it boil down to satisfying people's vanity. It solves no problem, it provides no useful benefit to humanity. It's the same with Valve making hats for TF2 and skins for CS:Go instead of focusing on making great new games with story and content and adventure. This AR tech is the equivalent of serving a poopie diaper in a 5-star restaurant and calling it "Powerful Foods to inspire the imagination." And people are eating it all up.
Is this what we are moving toward?