Use iOS 8 default blur view

// -- add blur effect
    UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
    
    UIVisualEffectView *blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
    
    [blurEffectView setFrame:self.view.bounds];
    
    
    [self.view addSubview:blurEffectView];

    //[self.view insertSubview:blurEffectView atIndex:0];