Fading view transition...

gistfile1.m

[CATransaction begin];

CATransition *transition = [CATransition animation];
transition.type = kCATransitionFade;
transition.duration = animated ? 0.5f : 0.0f;
transition.fillMode = kCAFillModeForwards;
transition.removedOnCompletion = YES;

[[UIApplication sharedApplication].keyWindow.layer addAnimation:transition forKey:@"transition"];        
[[UIApplication sharedApplication] beginIgnoringInteractionEvents];
[CATransaction setCompletionBlock: ^ {
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(transition.duration * NSEC_PER_SEC)), dispatch_get_main_queue(), ^ {
        [[UIApplication sharedApplication] endIgnoringInteractionEvents];        
    });
}];

[self presentModalViewController:someVC animated:NO];

[CATransaction commit];