UIMotionEffect setup on multiple views

gistfile1.m

    // Setup horizontal motion effect
    UIInterpolatingMotionEffect *horizontalInterpolation = [[UIInterpolatingMotionEffect alloc] initWithKeyPath:@"center.x" type:UIInterpolatingMotionEffectTypeTiltAlongHorizontalAxis];
    horizontalInterpolation.minimumRelativeValue = @-kMotionViewControllerInterpolationValue;
    horizontalInterpolation.maximumRelativeValue = @kMotionViewControllerInterpolationValue;
    
    // Setup vertical motion effect
    UIInterpolatingMotionEffect *verticalInterpolation = [[UIInterpolatingMotionEffect alloc] initWithKeyPath:@"center.y" type:UIInterpolatingMotionEffectTypeTiltAlongVerticalAxis];
    verticalInterpolation.minimumRelativeValue = @-kMotionViewControllerInterpolationValue;
    verticalInterpolation.maximumRelativeValue = @kMotionViewControllerInterpolationValue;
    
    // Add squares view
    for (NSInteger i=0; i<6; i++)
    {
        NSInteger row = i/3;
        NSInteger column = i%3;
        UIView *squareView = [[UIView alloc] initWithFrame:CGRectMake(20 + column*100, 100 + row*100, 80, 80)];
        [squareView setBackgroundColor:[UIColor colorWithRed:row*100.0f/255.0f green:column*50.0f/255.0f blue:0.5f alpha:1.0f]];
        [squareView addMotionEffect:horizontalInterpolation];
        [squareView addMotionEffect:verticalInterpolation];
        [self.view addSubview:squareView];
    }