To specify which storyboard to load, do so in your AppDelegate
's application:didFinishLaunchingWithOptions:
method.
Load the storyboard that corresponds to the screen size using its storyboard name, ex:
UIStoryboard *storyboard;
CGSize screenSize = [[UIScreen mainScreen] bounds].size;
if (screenSize.height == 568) {
// iPhone 5, i.e. 568 pixels high
storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone5" bundle:nil];
} else {
// earlier model iPhones, i.e. 480 pixels high
storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone4" bundle:nil];
}
UIViewController *initialViewController = [storyboard instantiateInitialViewController];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = initialViewController;
[self.window makeKeyAndVisible];