Show spash screen each time app becomes active

I want the splash screen to be displayed each time app becomes active. I have created a function showSplash which I call in applicationDidBecomeActive

-(void)showSplash
{
    UIImageView *splashScreen = [[UIImageView alloc] initWithImage:[UIImage imageNamed: @"Default.png"]];
    [self.window.rootViewController.view addSubview: splashScreen];
    [self.window makeKeyAndVisible];
    NSLog(@"begin splash");
    [UIView animateWithDuration: 4.2
                          delay: 0.5
                        options: UIViewAnimationOptionCurveEaseOut
                     animations: ^{  
                         splashScreen.alpha = 0.0;
                     }
                     completion: ^ (BOOL finished) {
                         [splashScreen removeFromSuperview];
                         NSLog(@"end splash");
                     }
     ];
}  

This is how I call this function :

- (void)applicationDidBecomeActive:(UIApplication *)application {
[self showSplash];
}

But no splash screen appears. Please correct me.