Apple Push Notification Service using example with Swift. Supports iOS7.

APNSTest.rb

# Install APNS gem:
# sudo gem install APNS
require 'APNS'

# gateway.sandbox.push.apple.com is default
# APNS.host = 'gateway.push.apple.com' # Production
APNS.host = 'gateway.sandbox.push.apple.com' # Development
    
# this is also the default. Shouldn't ever have to set this, but just in case Apple goes crazy, you can.
APNS.port = 2195 

# this is the certificate file
APNS.pem  = 'APNSTestingCert-Dev.pem'

device_token = 'YourLongDeviceTokenGoesHere'

APNS.send_notification(device_token, 'Hello iPhone!' )
# APNS.send_notification(device_token, :alert => 'Hello iPhone!', :badge => 1, :sound => 'default')

AppDelegate.swift

let SETTINGS_KEY_DEVICE_TOKEN = "com.example.deviceToken"

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.
        
        // ios8
        if (UIApplication.sharedApplication().respondsToSelector(Selector("registerForRemoteNotifications")))
        {
            var types: UIUserNotificationType = UIUserNotificationType.Badge |
                UIUserNotificationType.Alert |
                UIUserNotificationType.Sound
            
            var settings: UIUserNotificationSettings = UIUserNotificationSettings( forTypes: types, categories: nil )
            
            application.registerUserNotificationSettings( settings )
            application.registerForRemoteNotifications()
        }
        // ios7
        else
        {
            application.registerForRemoteNotificationTypes( UIRemoteNotificationType.Badge |
                UIRemoteNotificationType.Sound |
                UIRemoteNotificationType.Alert )
        }
        
        return true
    }

    func application(application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData)
    {
        println("Got token data! \(deviceToken)")
        
        var characterSet: NSCharacterSet = NSCharacterSet( charactersInString: "<>" )
        
        var deviceTokenString: String = ( deviceToken.description as NSString )
            .stringByTrimmingCharactersInSet( characterSet )
            .stringByReplacingOccurrencesOfString( " ", withString: "" ) as String
        
        println( deviceTokenString )
        NSUserDefaults.standardUserDefaults().setObject(deviceTokenString, forKey: SETTINGS_KEY_DEVICE_TOKEN)
        NSNotificationCenter.defaultCenter().postNotificationName(SETTINGS_KEY_DEVICE_TOKEN, object: nil)
    }
    
    func application(application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: NSError)
    {
        println("Couldn't register: \(error)")
        UIAlertView(title: "Error", message: "Couldn't register: \(error)", delegate: nil, cancelButtonTitle: "Ok").show()
    }
    
        func applicationWillResignActive(application: UIApplication) {
    }

    func applicationDidEnterBackground(application: UIApplication) {
    }

    func applicationWillEnterForeground(application: UIApplication) {
    }

    func applicationDidBecomeActive(application: UIApplication) {
    }

    func applicationWillTerminate(application: UIApplication) {
    }

}

ViewController.swift

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var lblDeviceAPNSToken: UILabel!
    var deviceToken: String? = ""

    override func viewDidLoad() {
        super.viewDidLoad()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("updateDeviceToken"), name: SETTINGS_KEY_DEVICE_TOKEN, object: nil)
        
        if (self.areNotificationsEnabled())
        {
            self.updateDeviceToken()
        }
        
        let tapRecognizer = UITapGestureRecognizer(target: self, action: Selector("shareDeviceToken"))
        self.lblDeviceAPNSToken.addGestureRecognizer(tapRecognizer)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
    
    func updateDeviceToken()
    {
        if let deviceToken: String = NSUserDefaults.standardUserDefaults().objectForKey(SETTINGS_KEY_DEVICE_TOKEN)? as? String
        {
            self.lblDeviceAPNSToken.text = deviceToken
            self.deviceToken = deviceToken
        }
    }
    
    @IBAction func shareDeviceToken()
    {
        var sharingItems = [AnyObject]()
        
        if let text = deviceToken {
            sharingItems.append(text)
        }
        
        let activityViewController = UIActivityViewController(activityItems: sharingItems, applicationActivities: nil)
        self.presentViewController(activityViewController, animated: true, completion: nil)
    }
    
    deinit
    {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    func areNotificationsEnabled() -> Bool
    {
        // ios8
        if (UIApplication.sharedApplication().respondsToSelector(Selector("currentUserNotificationSettings")))
        {
            let noticationSettings = UIApplication.sharedApplication().currentUserNotificationSettings()
            if (noticationSettings == nil
            || noticationSettings.types == UIUserNotificationType.None)
            {
                return false
            }
            
            return true
        }
        
        // ios7
        let types = UIApplication.sharedApplication().enabledRemoteNotificationTypes()
        if (types == nil || types == UIRemoteNotificationType.None)
        {
            return false
        }
        else
        {
            return true
        }
    }
}