title: Detect if the app was launched/opened from a push notification
body: <p>Is it possible to know if the app was launched/opened from a push notification?</p>
  
  <p>I guess the launching event can be caught here:</p>
  
  <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  
      if (launchOptions != nil) {
           // Launched from push notification
           NSDictionary *notification = [launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
  
      }
  }
  </code></pre>
  
  <p>However, how can I detect it was opened from a push notification when the app was in background?</p>