Providing API for communicating with a running application?

Basically I'm trying to find a solution to my issue with sharing an开发者_JAVA技巧 object. I've had a look at SpringBoard's implementation and it looks as if SpringBoard is providing a framework which can be used to retrieve SBDisplay objects (which are basically CALayers).

I know this specific issue is related to iPhones, but I also know that this is also used by a lot of Cocoa software. Could someone point out a way to copy such behaviour?

App 1 (Application launcher) :

• Launches client applications
• Has the main CALayer object
• Serves as the window server

App 2 (Client app) :

• Needs the main CALayer from App1 to render itself onto

And again, just to reiterate - I am fully aware of AppStore policies. And yes, I am using a jailbroken device.