Its when you are more than happy about a new application for your android. You are hyappy
After using some kind of drug that raises your activity level, and you want to use an android application.
Man I am so Hyappy today!!! I can take on the world... with this new android application!! It makes me so HYAPPY
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"