gistfile1.m

// based on and inspired by https://gist.github.com/1026439 and https://gist.github.com/3798781
//
// MIT license. Use however you'd like.
//
// first, define our macro for delaying our transition:
#define PKWaitDelay(dly, block)     dispatch_after(dispatch_time(DISPATCH_TIME_NOW,dly*100000),dispatch_get_current_queue(), ^{ block })

// then, inside your AppDelegate.m in didFinishLaunchingWithOptions:

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.window.frame];
    
    if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad )
    {
        switch ( [[UIApplication sharedApplication] statusBarOrientation] )
        {
        case UIInterfaceOrientationLandscapeLeft:
        case UIInterfaceOrientationLandscapeRight:
                if ( [UIScreen mainScreen].scale == 2 ) { imageView.image = [UIImage imageNamed:@"Default-Landscape@2x~ipad.png"]; }
                                                   else { imageView.image = [UIImage imageNamed:@"Default-Landscape~ipad.png"]; }
                [imageView setFrame: CGRectMake(0, 0, 1024, 748) ];
            break;
        case UIInterfaceOrientationPortrait:
        case UIInterfaceOrientationPortraitUpsideDown:
                if ( [UIScreen mainScreen].scale == 2 ) { imageView.image = [UIImage imageNamed:@"Default-Portrait@2x~ipad.png"]; }
                                                   else { imageView.image = [UIImage imageNamed:@"Default-Portrait~ipad.png"]; }
                [imageView setFrame: CGRectMake(0, 0, 768, 1004) ];
            break;
        }
    }
    else
    {
        // we're an iPhone or iPod touch. No rotation for you.
        if ( [UIScreen mainScreen].scale == 2 )
        {
            // are we a 3.5in? or a 4?
            if ([UIScreen mainScreen].bounds.size.height == 568.0f)
            {
                // 4 inch iPhone 5
                imageView.image = [UIImage imageNamed:@"Default-568h@2x.png"];                
                [imageView setFrame: CGRectMake(0, 0, 320, 548) ];
            }
            else
            {
                imageView.image = [UIImage imageNamed:@"Default@2x.png"];
                [imageView setFrame: CGRectMake(0, 0, 320, 460) ];
            }
        }
        else
        {
            imageView.image = [UIImage imageNamed:@"Default.png"];
            [imageView setFrame: CGRectMake(0, 0, 320, 460) ];
        }
    }
    [self.window.rootViewController.view addSubview:imageView];
    [self.window.rootViewController.view bringSubviewToFront:imageView];

    PKWaitDelay(2,{
    [UIView transitionWithView:self.window
                      duration:1.00f
                       options:UIViewAnimationCurveEaseInOut
                    animations:^(void){
                        imageView.alpha = 0.0f;
                    }
                    completion:^(BOOL finished){
                        [imageView removeFromSuperview];
                    }];}
           );
    [self.window makeKeyAndVisible];