Blurring sensitive data

AppDelegate+Blur.m

#pragma mark - Security
- (void)applicationDidEnterBackground:(UIApplication *)application {
    RootViewController *rootVC = (RootViewController *)self.window.rootViewController;
    UIViewController *viewController = (UIViewController *)[rootVC.presentedViewControllers lastObject];
  /**
    If the last presented view controller is a SplashViewController we must not present the splash
    screen again.
  */
 if (![viewController isKindOfClass:[SplashViewController class]]) {
    /**
      We're presenting a splash screen when the app backgrounds as a privacy and security feature.
      This view needs to block the UI so that a screenshot of sensitive data does not accidentally
      get saved to the background.
    */
    [self presentSplashViewController];
  }
}