// controller
public function send_gcm()
{
	// simple loading
	// note: you have to specify API key in config before
		$this->load->library('gcm');
	
	// simple adding message. You can also add message in the data,
	// but if you specified it with setMesage() already
	// then setMessage's messages will have bigger priority
		$this->gcm->setMessage('Test message '.date('d.m.Y H:s:i'));
		
	// add recepient or few
		$this->gcm->addRecepient('RegistrationId');
		$this->gcm->addRecepient('New reg id');
	
	// set additional data
		$this->gcm->setData(array(
			'some_key' => 'some_val'
		));
	
	// also you can add time to live
		$this->gcm->setTtl(500);
	// and unset in further
		$this->gcm->setTtl(false);
	
	// set group for messages if needed
		$this->gcm->setGroup('Test');
	// or set to default
		$this->gcm->setGroup(false);
	
	// then send
		if ($this->gcm->send())
			echo 'Success for all messages';
		else
			echo 'Some messages have errors';
	
	// and see responses for more info
		print_r($this->gcm->status);
		print_r($this->gcm->messagesStatuses);
			
	die(' Worked.');
}