With the rise of different apps, which hijack the iOS simulator (such as flawless or now sherlock) I'm curious how this is done.
As far as I've found there were options based on SIMBL but I don't think the above use it. Further more there is Injection (https://github.com/johnno1962/injectionforxcode) which uses XPC's to inject code.
I would guess there are different ways (e.g. how is the UI change done? both either the flawless layer on top of it, or the variable change in sherlock) so it would be great if someone here would point me in the right direction.