I am trying to display a welcome message when the user launches the app. I am using the `UIAlertController` class.

I am adding the `UIAlertController` in app delegate, here it is

```
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:[[ViewController alloc] init]];

    [self.window makeKeyAndVisible];

    UIAlertController *alertMessage = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Welcome!", @"Welcome")
                                                                          message:@"Enjoy Using the Browser"
                                                                   preferredStyle:UIAlertControllerStyleAlert];

    return YES;
}

```

I get the warning that `alertMessage` is not being used. I don't know how to go forward, any hints or tips?