People who stay on the cutting edge of i-phone / smart-phone apps, and who always have the latest app for any imaginable function downloaded to their phone. Rhymes with literati, glitterati, digerati, etc. Has the virtue of also being the Latin for apparatuses, which the apparati, of course, always have in plentiful supply to run all their apps.
Dude 1: "Dude, I just downloaded an app that organizes app-organizing apps according to the compass direction that points from my position to the GPS coordinates of ISP used by the developer of the app."
Dude 2: "Dude, You have officially joined the apparati."