'preloading' for ios?

I'm currently running into a problem with my application where in when it first boots up on the device (iOS), it initially runs fairly slow.  After a second or two, its fine and runs a quick as you please.

I can only guess that it is continuing to load in data to RAM after the initial native 'default loading' screen. And during this process it is running slowly (until it finishes loading all its data).

I'm not loading any external data into my application. Everything is contained in one SWF and assets are linked in from a single library.

I've delt with creating loaders that load external data into a .swf (imgs, external swfs, etc).  I'm curious if there is a method to check weather or not the application has fully loaded? Preferably via code and no funky timeline tricks. With this I could then make a loading screen.

Worst case scenario I just make loading screen that is merely a timer to give the application the couple of seconds it needs to finish loading up, but I would prefer to do it the correct way.

Thanks,

dis