Debug/Run extensions

Hi everyone,
I've just discovere app code and I would like to try it because its really interesting to me.

Currently I'm developing an iOS8 extension (a keyboard).
With Xcode I was able to select the keyboard target and run/debug the keyboard directly..

It is possible with appcode too?
I create the run configuration but I'm not able either to leave the executable field empty (I do that in Xcode) or to select a simulator app like safari.

Thank you for your help!

Mauro