I may be firing in the dark but I want to know some insights into how the Chatter Desktop and Chatter mobile apps (such as iOS & Android) work. Do these tools use Chatter Connect API? I ask this because I know of an org (public) where Chatter Connect API is disabled but these apps still work perfectly.
Since the Chatter Connect API is disabled, my third-party Chatter app does not work on this org. Since the standard Chatter Desktop and Chatter Mobile apps do work (despite Chatter Connect API being disabled), I'm starting to believe that these tools use another mechanism.
I'll appreciate if any Chatter experts can throw some light on this.
Update - Thank you for all the answers, this is now well explained in the Chatter Connect documentation