If you want to navigate on another app through the notification, use these methods didFinishLaunchingWithOptions: , didReceiveRemoteNotification: from your app delegate; use this example:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:
                                                 (NSDictionary *)launchOptions {
   self.window.rootViewController = self.tabBarController;
   [self.window makeKeyAndVisible];
   // If application is launched due to  notification, present another view controller.
   UILocalNotification *notification = [launchOptions objectForKey:
                                        UIApplicationLaunchOptionsRemoteNotificationKey];
   if(notification) {
      NotificationViewController *viewController = [
                                        [NotificationViewController alloc]initWithNibName:
                                         NSStringFromClass([NotificationViewController class])
                                         bundle:nil];
      [self.window.rootViewController presentModalViewController:
                                         viewController animated:NO];
      [viewController release];
   }
   return YES;
}
 -(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
   NotificationViewController *viewController = [[NotificationViewController alloc]initWithNibName:NSStringFromClass([NotificationViewController class]) bundle:nil];
   [self.window.rootViewController presentModalViewController:viewController animated:NO];
   [viewController release];
}