Add-ons?

Hey, is this the deluxe version or something cuz i found the robes of altair and you would usually have to download that from uplay so whats up? are add-ons included? It is making me angry because I cant get add-ons from steam cuz this game is from the app=store. you guys should realyl consider putting add-ons on the app store, it would be very nice. thanks

Chaaadd about Assassin's Creed II