Similar to a person who is going "Ape-shit". Individuals who are going App-shit in many cases appear to be in an out control frenzy, often buying pointless apps they will never use more than once just to show them off to their friends and co-workers.
Friend 2: "Ha ha ha ha ha! Dude! I went totally App-shit too when I first got my IPhone. I wasted like 50 bucks in two days on Apps I deleted like two weeks later. Don't trip, he'll snap out of it after a week or so."
Overwhelming; intensely enthusiastic; passionately excited desire to download every application that seems remotely interesting on a new mobile smart device.
Addictively involved in the downloading of apps.