Juvenile? Maybe. But it's still fun to see what your phone thinks you or your friends would look like if you put on 150 pounds. Snap a shot of someone's face, then tap the eyes, mouth, and chin. The app magically adds the weight. Funny ha-ha but also kind of funny eww.
WIRED Shake phone to see before and after views. Resulting photos are realistic enough to be both a joke and an incentive to diet.
TIRED Novelty wears off real fast.