Perform Segue on ViewDidLoad

In iOS 5 I have a Storyboard with a modal view controller, that I would like to display if its the user's first time in the app, after that I would like to skip this view controller.

I set an NSDefault key to handle this but when I check to see if this is set and then use performSegueWithIdentifier to initiate the segue, nothing happens. If i put this segue behind a button it works fine...

I answered a similar question where the developer wanted to show a login screen at the start. I put together some sample code for him that can be downloaded here. The key to solving this problem is calling things at the right time if you want to display this new view controller, you will see in the example you have to use something like this

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
    [vc setModalPresentationStyle:UIModalPresentationFullScreen];

    [self presentModalViewController:vc animated:YES];
}

I also have an explanation of how segues and storyboards work that you can see here

Loading in ViewDidLoad caused "under-layer" to flash. I solved this by loading my Storyboard programmatically. Thus, under Target/Main Storyboard - leave this blank. Then add the following:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    // Load Main App Screen
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    HomeScreenVC *homeScreenVC = [storyboard instantiateInitialViewController];
    self.window.rootViewController = homeScreenVC;
    [self.window makeKeyAndVisible];

    // Load Login/Signup View Controller
    UIViewController *mainLoginVC = [storyboard instantiateViewControllerWithIdentifier:@"MainLoginVC"];
    [mainLoginVC setModalPresentationStyle:UIModalPresentationFullScreen];
    [homeScreenVC presentModalViewController:mainLoginVC animated:NO];

    return YES;
}

The problem is you are adding a second view to the hierarchy before the first is fully added. Try putting your code in:

-(void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];
    // Present your modal from here
}

After [super viewDidAppear] is called you have a fully loaded view to modify.