One who incessantly uses the text feature on a cell phone to send text messages to an individual or a group advising the recipient(s) of their most mundane accomplishments.
Dude, Maggie the "serial texter" just sent me a message that she got her haircut; what's next, a text that she just dropped a deuce ?
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?"