#pragma mark -
#pragma mark Puzzles 
-(void)openPuzzles {
	if (myPuzzleDelegate == nil) {
		myPuzzleDelegate = [[PuzzleDelegate alloc] initWithNibName:@"PuzzleMainView" bundle:nil];
		[self.view addSubview:myPuzzleDelegate.view];
		[myPuzzleDelegate initWithParent:self];
		myPuzzleDelegate.view.alpha = 0.0;
		[UIView beginAnimations:nil context:NULL];
		[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
		[UIView setAnimationDelegate:self];
		[UIView setAnimationDidStopSelector:@selector(puzzlesFadedIn:finished:context:)];
		[UIView setAnimationDuration:0.5];
		myPuzzleDelegate.view.alpha = 1.0;
		[UIView commitAnimations];
	}
}

-(void)puzzlesFadedIn:(NSString*)animationID finished:(NSNumber*)finished context:(void*)context {
	//
}

Loading ViewController with CoreAnimation

Objective C