Optimizing iPhone Application Launch Time
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 becomes usable in a snappy manner?
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.
I use lots of external resources, so I use Lazy loading to get up and running quickly. This way the APP can start with the barest minimum and then load the rest while its already begun.
Made a big difference in start time
This is one of those things where there is no sure-fire path to success. Use Apple's excellent Instruments tool to monitor your application's launch. You then need to delve into the results to figure out ways to optimise the launch process.
Also try profiling with Shark, to find any performance bottlenecks.