ApiRequestExample.swift

//
//  ViewController.swift
//  apirequest
//
//  Created by Andre Cardoso on 9/24/15.
//

import UIKit
import Foundation

class ViewController: UIViewController {
    
    @IBOutlet weak var phone: UITextField!
    @IBOutlet weak var email: UITextField!
    

    @IBAction func obterLista() {
        
        // Exemplo de GET
        
        // Setando a URL
        let endpoint = NSURL(string: "http://0.0.0.0/api/v1/listar-algo")
        
        // Obtendo o retorno da URL
        let data = NSData(contentsOfURL: endpoint!)
        
        // Processando o retorno JSON
        if let json: NSDictionary = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary {
            
            // Obtendo a resposta dentro de "content" (ou outra chave que o server retorne) como um array
            if let items = json["content"] as? NSArray {
                
                // Loop dos itens
                for item in items {
                    let title: AnyObject! = item["title"]
                    let id: AnyObject! = item["id"]
                    
                    let elemento = "ID: \(id) Nome: \(title) \r\n"
                    print(elemento)
                }
                
            }
        }
        
        // Exemplo de GET
        
    }
    
    @IBAction func enviarDados() {
        
        // Callback para atualização da UITextView
        let atualizaUITextView = {(textString: String) in
            dispatch_sync(dispatch_get_main_queue()) {
              self.textViewLojas.text = textString
            }
        }
        
        // Obtendo os valores digitados
        let phone: AnyObject! = self.phone.text
        let email: AnyObject! = self.email.text
        let deviceId = UIDevice.currentDevice().identifierForVendor!.UUIDString
        
//        print(phone)
//        print(email)
//        print(deviceId)
        
        // Setando a URL
        let request = NSMutableURLRequest(URL: NSURL(string: "http://0.0.0.0/api/v1/url-de-post")!)
        
        // Informando que o método de requisição é POST
        request.HTTPMethod = "POST"
        
        // Setando os dados do post
        let postString = "phone=\(phone)&deviceId=\(deviceId)&email=\(email)"
        request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
        
        // Iniciando a chamada à  API
        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
            data, response, error in
            
            if error != nil {
                print("error=\(error)")
                return
            }
            
            //print("response = \(response)")
            
            var respostaPost = ""
            
            // Processando o retorno JSON
            if let json: NSDictionary = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary {
                
                let dados = json["content"]
                
                let token: String! = dados?["token"] as! String
                
                respostaPost += "Token: \(token) \r\n"
                
                atualizaUITextView(respostaPost)
                
            }
        }
        
        // realizando a requisição
        task.resume()
    }
    
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

Info.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	... todas as definições já existentes no arquivo ...
	<key>NSAppTransportSecurity</key>
    <dict>
           <key>NSAllowsArbitraryLoads</key>
          <true/>
   </dict>
</dict>
</plist>