They use a bunch of different in-house internet, all copyrighted to the Genius Bar and Apple. I know they have a battery analysis application that looks at the data in the Battery portion of the System_Profiler.app, but apart from that, I don't know. They also run basic diagnostic tools, like TechTools Deluxe from AppleCare, and the general ways of looking through your iPhone (like DFU mode, restores, manual settings, etc.)
There's no way you're gonna be able to find it online, any Apple employee would get fired immediately for distributing it.