AppDelegate with push notifications implemented

AppDelegate.swift

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, GGLInstanceIDDelegate {

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        
        // register for push notifications
        var types = UIUserNotificationType.Alert | UIUserNotificationType.Sound | UIUserNotificationType.Badge
        var settings = UIUserNotificationSettings(forTypes: types, categories: nil)
        application.registerUserNotificationSettings(settings)
        application.registerForRemoteNotifications()
        
        // set up NexmoClient
        NexmoClient.start(applicationId: "app", sharedSecretKey: "key")
        return true
    }
    
    func application(application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {
    
        // this callback returns our APNS device token which we then forward to GCM 
        // so we can receive push notifications from them
        apnDeviceDoken = deviceToken
        var instanceIDConfig = GGLInstanceIDConfig.defaultConfig()
        instanceIDConfig.delegate = self
        GGLInstanceID.sharedInstance().startWithConfig(instanceIDConfig)
        var registrationOptions = [kGGLInstanceIDRegisterAPNSOption:deviceToken,
                                   kGGLInstanceIDAPNSServerTypeSandboxOption:true]
        GGLInstanceID.sharedInstance().tokenWithAuthorizedEntity(gcmSenderId, scope: kGGLInstanceIDScopeGCM, options: registrationOptions, handler: self.handleToken)
    }
    
    func handleToken(token: String!, error: NSError!) {
        // this function is the callback for our GCM token which will be used by sdk service to send push
        // notifications to this specifid device
        NexmoClient.setGcmToken(token)
        println("gcmToken = \(token)")
    }
    
    func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
        // this callback receives ALL push notifications sent to this specific device
        // from ALL sources
        GCMService.sharedInstance().appDidReceiveMessage(userInfo)
        if let pin = userInfo["pin"] as? String {
            println("received pin code \(pin)")
        }
    }
}