As anyone with an iPhone knows, some applications launch quickly, while others take several seconds.
What are the best techniques for ensuring an iPhone app launches and
Apple recommends you "lazy load" every view. I.e. only load the first page on start up, and other pages only when they are navigated to.
In terms of graphics, use PNGs wherever possible as the device is heavily optimized for this format.
Also include the startup screenshot so the user knows the application is loading.