This tip is only meant to reduce your effort on developing iPhone/iPad application.
Basically in an app you developed a logic that on run time you need to delete some resource from NSBundle time(which is through coding).As initailly the application is run on simulator by most developers.it will work perfectly with no issue.
But when you run the same application on device i.e iPhone/iPad it will show a error i,e NSCocoaErrorDomain = 513.
What it means is that on runtime in device the bundle has only read permisson not write.
So when designing the applications do not include logic that deletes the resource from NSBundle on run time because it will work perfectly in iPhone/iPad simulator.