Development on Linux
From Elite Wiki
Setting up the development environment
Do as you wish :-)
I use vim + youcompleteme.
There's no IDE on linux managing objective-c (at least not Eclipse and Intellij). Auto-completion doesn't work in most of them because the xCode libraries aren't available (they're on OS X).
The only plugin for objective-c on eclipse is discontinued.
You can see the call hierarchy in the doxygen documentation at https://ooliteproject.github.io/oolite/
Some use Emacs.