As parents drift off to the sound some quaintly call typing, their children are deep inside multiple conversations with their “buddies,” pseudonymous pals listed vertically along one side of the screen. Pull a stealth P.O.S. (parent over shoulder) and you might catch a few screen alter egos — for instance, shebiscuit, kickflip10, latteladie, talkinghead88, Jesusraves, each with individualized sign-on sounds, audio cues reminiscent of the way each character in “Peter and the Wolf” is represented by its own instrument.