diff --git a/.gitignore b/.gitignore
index 6b6e772..03a2edd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
 vendor/
 composer.lock
 .idea
-src/Config/config.php
 src/Config/iosCertificates/ck.pem
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..ad20d09
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,26 @@
+#   ChangeLog
+
+##  v2.0
+
+Now you can create the object with the push service provider only typing the name
+
+    $push = new PushNotification('apn');
+
+Addition of a new Push service provider : FCM
+
+    $push = new PushNotification('fcm');
+
+As previous versions, if you instance the class without argument. it will set GCM as default Push service provider
+
+    $push = new PushNotification();
+
+
+##  v1.0
+
+Usage
+
+    $push = new PushNotification;
+
+or for APN
+
+    $push = new PushNotification(new \Edujugon\PushNotification\Apn());
diff --git a/readme.md b/readme.md
index fab4d8f..10567b0 100644
--- a/readme.md
+++ b/readme.md
@@ -2,11 +2,16 @@
 
 This is a lightly and easy to use package to send push notification.
 
-## Instalation
+## Installation
 
-Update your composer.json file.
+type in console:
 
-    "edujugon/push-notification": "dev-master"
+        composer require edujugon/push-notification
+
+
+Or update your composer.json file.
+
+    "edujugon/push-notification": "^2.0.*"
 
 Then
 
@@ -38,15 +43,20 @@ Publish the package's configuration file to the application's own config directo
 
 By default it will use GCM as Push Service provider.
 
-If you want to use APNS:
+For APN Service:
+
+    $push = new PushNotification('apn');
+
+For FCM Service:
+
+    $push = new PushNotification('fcm');
 
-    $push = new PushNotification(new \Edujugon\PushNotification\Apn());
 
 ### Push Service configuration
 
 The default configuration for all Push service providers is located in Config/config.php
 
-The default configuration parameters for **GCM** are :
+The default configuration parameters for **GCM** and **FCM** are :
 
 *   priority => normal
 *   dry_run => false
@@ -60,7 +70,7 @@ You can dynamically update those values or adding new ones calling the method se
     ]);
 
 
-The default configuration parameters for **APNS** are:
+The default configuration parameters for **APN** are:
 
 *   certificate => __DIR__ . '/iosCertificates/yourCertificate.pem'
 *   passPhrase => 'MyPassPhrase'
@@ -90,7 +100,7 @@ GCM sample:
                     ->setApiKey('Server-API-Key')
                     ->setDevicesToken(['deviceToken1','deviceToken2','deviceToken3'...]);
 
-APNS sample:
+APN sample:
 
     $push->setMessage([
                 'aps' => [
diff --git a/src/Apn.php b/src/Apn.php
index 832eeff..5968151 100644
--- a/src/Apn.php
+++ b/src/Apn.php
@@ -11,21 +11,21 @@ class Apn extends PushService implements PushServiceInterface
      *
      * @var string
      */
-    private $sandbox_url = 'ssl://gateway.sandbox.push.apple.com:2195';
+    private $sandboxUrl = 'ssl://gateway.sandbox.push.apple.com:2195';
 
     /**
      * Url for production
      *
      * @var string
      */
-    private $production_url = 'ssl://gateway.push.apple.com:2195';
+    private $productionUrl = 'ssl://gateway.push.apple.com:2195';
 
     /**
      * Apn constructor.
      */
     public function __construct()
     {
-        $this->url = $this->production_url;
+        $this->url = $this->productionUrl;
 
         $this->config = $this->initializeConfig('apn');
     }
@@ -44,9 +44,9 @@ public function setConfig(array $config)
         {
             if($this->config['dry_run']){
 
-                $this->setUrl($this->sandbox_url);
+                $this->setUrl($this->sandboxUrl);
 
-            }else $this->setUrl($this->production_url);
+            }else $this->setUrl($this->productionUrl);
         }
     }
 
diff --git a/src/Config/config.php b/src/Config/config.php
index 10bebe8..d13dd9a 100644
--- a/src/Config/config.php
+++ b/src/Config/config.php
@@ -5,6 +5,10 @@
       'priority' => 'normal',
       'dry_run' => false
   ],
+  'fcm' => [
+        'priority' => 'normal',
+        'dry_run' => false
+  ],
   'apn' => [
       'certificate' => __DIR__ . '/iosCertificates/ck.pem',
       'passPhrase' => '123456',
diff --git a/src/Contracts/PushServiceInterface.php b/src/Contracts/PushServiceInterface.php
index cfa8ef7..f65aead 100644
--- a/src/Contracts/PushServiceInterface.php
+++ b/src/Contracts/PushServiceInterface.php
@@ -6,16 +6,53 @@
 interface PushServiceInterface
 {
 
+    /**
+     * Set the url to connect with the Push service provider.
+     * 
+     * @param $url
+     * @return mixed
+     */
     function setUrl($url);
 
+    /**
+     * Set the API KEY to connect with the Push service provider.
+     *
+     * @param $api_key
+     * @return mixed
+     */
     function setApiKey($api_key);
 
+    /**
+     * Set the Push service provider configuration.
+     *
+     * @param array $config
+     * @return mixed
+     */
     function setConfig(array $config);
 
+    /**
+     * Set the Push Notification Response.
+     *
+     * @param $feedback
+     * @return mixed
+     */
     function setFeedback($feedback);
 
+    /**
+     * Send the notification
+     *
+     * @param array $deviceTokens
+     * @param array $message
+     * @return mixed
+     */
     function send(array $deviceTokens, array $message);
 
+    /**
+     * Retrieve the device tokes that couldn't receive the message from the push notification.
+     *
+     * @param array $devices_token
+     * @return mixed
+     */
     function getUnregisteredDeviceTokens(array $devices_token);
 
 }
\ No newline at end of file
diff --git a/src/Fcm.php b/src/Fcm.php
index c1425de..7d8723b 100644
--- a/src/Fcm.php
+++ b/src/Fcm.php
@@ -2,13 +2,17 @@
 namespace Edujugon\PushNotification;
 
 
+use GuzzleHttp\Client;
+
 class Fcm extends Gcm
 {
 
     public function __construct()
     {
-        parent::__construct();
-
         $this->url = 'https://fcm.googleapis.com/fcm/send';
+
+        $this->config = $this->initializeConfig('fcm');
+        
+        $this->client = new Client();
     }
 }
\ No newline at end of file
diff --git a/src/Gcm.php b/src/Gcm.php
index 0e1d114..42a68c6 100644
--- a/src/Gcm.php
+++ b/src/Gcm.php
@@ -66,7 +66,7 @@ protected function addRequestFields($deviceTokens,$message){
 
     protected function addRequestHeaders(){
         return [
-            'Authorization' => 'key=' . $this->api_key,
+            'Authorization' => 'key=' . $this->apiKey,
             'Content-Type:' =>'application/json'
         ];
     }
diff --git a/src/PushNotification.php b/src/PushNotification.php
index 9f50161..a84d93c 100644
--- a/src/PushNotification.php
+++ b/src/PushNotification.php
@@ -2,8 +2,6 @@
 namespace Edujugon\PushNotification;
 
 
-use Edujugon\PushNotification\Contracts\PushServiceInterface;
-
 class PushNotification
 {
 
@@ -18,18 +16,25 @@ class PushNotification
      *
      * @var array
      */
-    protected $service_collection = [
+    protected $servicesList = [
         'gcm' => Gcm::class,
         'apn' => Apn::class,
         'fcm' => Fcm::class
     ];
 
+    /**
+     * The default push service to use.
+     *
+     * @var string
+     */
+    private $defaultServiceName = 'gcm';
+
     /**
      * Devices' Token where send the notification
      *
      * @var array
      */
-    protected $devices_token = [];
+    protected $deviceTokens = [];
 
     /**
      * data to be sent.
@@ -40,12 +45,15 @@ class PushNotification
 
     /**
      * PushNotification constructor.
-     * @param PushServiceInterface $service By default GCM
+     * @param String / a service name of the services list.
      */
     public function __construct($service = null)
     {
-        $this->service = !is_null($service) ? $this->service_collection[$service] : new Fcm;
-        var_dump($this->service);
+        if(!array_key_exists($service,$this->servicesList)) $service = $this->defaultServiceName;
+        
+        $this->service = is_null($service) ? new $this->servicesList[$this->defaultServiceName]
+                                            : new $this->servicesList[$service];
+
     }
     
     /**
@@ -63,12 +71,12 @@ public function setMessage(array $data)
 
 
     /**
-     * @param array/string $devices_token
+     * @param array/string $deviceTokens
      * @return $this
      */
-    public function setDevicesToken($devices_token)
+    public function setDevicesToken($deviceTokens)
     {
-        $this->devices_token = is_array($devices_token) ? $devices_token : array($devices_token);
+        $this->deviceTokens = is_array($deviceTokens) ? $deviceTokens : array($deviceTokens);
 
         return $this;
     }
@@ -102,7 +110,7 @@ public function setConfig(array $config)
      */
     public function getUnregisteredDeviceTokens()
     {
-        return $this->service->getUnregisteredDeviceTokens($this->devices_token);
+        return $this->service->getUnregisteredDeviceTokens($this->deviceTokens);
     }
 
     /**
@@ -113,7 +121,7 @@ public function getUnregisteredDeviceTokens()
      */
     public function send(){
 
-        return $this->service->send($this->devices_token,$this->message);
+        return $this->service->send($this->deviceTokens,$this->message);
 
     }
 
diff --git a/src/PushService.php b/src/PushService.php
index 4f4310c..01733a4 100644
--- a/src/PushService.php
+++ b/src/PushService.php
@@ -26,7 +26,7 @@ abstract class PushService
      *
      * @var string
      */
-    protected $api_key = '';
+    protected $apiKey = '';
 
     /**
      * Push Server Response
@@ -43,11 +43,11 @@ public function setUrl($url)
     }
 
     /**
-     * @param string $api_key
+     * @param string $apiKey
      */
-    public function setApiKey($api_key)
+    public function setApiKey($apiKey)
     {
-        $this->api_key = $api_key;
+        $this->apiKey = $apiKey;
     }
 
     /**
diff --git a/tests/PushNotificationTest.php b/tests/PushNotificationTest.php
index b3c14bb..27a81a3 100644
--- a/tests/PushNotificationTest.php
+++ b/tests/PushNotificationTest.php
@@ -5,6 +5,14 @@
 
 class PushNotificationTest extends PHPUnit_Framework_TestCase {
 
+    /** @test */
+    public function push_notification_instance_creation_without_argument_set_gcm_as_service()
+    {
+        $push = new PushNotification();
+
+        $this->assertInstanceOf('Edujugon\PushNotification\Gcm',$push->service);
+    }
+
     /** @test */
     public function assert_send_method_returns_an_stdClass_instance()
     {
@@ -148,14 +156,32 @@ public function fcm_assert_send_method_returns_an_stdClass_instance()
         $push = new PushNotification('fcm');
 
         $push->setMessage(['message'=>'Hello World'])
-            ->setApiKey('AIzaSyAjsu5h5TLe9_q33zn2Q4a84N9KyCxCB04')
-            ->setDevicesToken(['dHoZVUu4T34:APA91bHJJxHTJMSNp95A3qAcMEbPqiS02UKAiXH0J8M-k7owtPf4XrW9k8QttT9pCLy_QzoxKQsJ4pwaSVEXHhowoPaqCPp1pvVsBZ6QUHoEtO_S9-Esel4N7nqeUypQ6ah8MKZKo6jl'])
+            ->setApiKey('asdfasdffasdfasdfasdf')
+            ->setDevicesToken(['asdfasefaefwefwerwerwer'])
             ->setConfig(['dry_run' => false]);
 
         $response = $push->send();
-        var_dump($response);
+
         $this->assertEquals('https://fcm.googleapis.com/fcm/send',$push->url);
         $this->assertInstanceOf('stdClass',$response);
 
     }
+
+    /** @test */
+    public function if_push_service_as_argument_is_not_valid_user_gcm_as_default()
+    {
+        $push = new PushNotification('asdf');
+
+        $this->assertInstanceOf('Edujugon\PushNotification\Gcm',$push->service);
+
+
+    }
+    /** @test */
+    public function get_available_push_service_list()
+    {
+        $push = new PushNotification();
+
+        $this->assertCount(3,$push->servicesList);
+        $this->assertInternalType('array',$push->servicesList);
+    }
 }
\ No newline at end of file