WatchKitBackgroundTask.swift

func application(application: UIApplication,
        handleWatchKitExtensionRequest userInfo: [NSObject : AnyObject]?, reply: (([NSObject : AnyObject]!) -> Void)!) {
            // This needs to be done to keep the app busy, before the process is killed bu the phone
            var workaround: UIBackgroundTaskIdentifier?
            workaround = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler({
                UIApplication.sharedApplication().endBackgroundTask(workaround!)
            })
            
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), {
                UIApplication.sharedApplication().endBackgroundTask(workaround!)
            })
            
            var realBackgroundTaks: UIBackgroundTaskIdentifier?
            realBackgroundTaks = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler({
                UIApplication.sharedApplication().endBackgroundTask(realBackgroundTaks!)
            })
            
            // Do here what you want to do, e.g. handle the request from the watch
            // reply([:])
            
            UIApplication.sharedApplication().endBackgroundTask(realBackgroundTaks!)
    }