title: can i use GCM (google cloud messaging) as sms gateway
body: <p>Actually I am developing an Android app for women security, its an emergency app which will send out panic messages to emergency contacts at the double click of power button of your phone, so at this double click event, only a request needs to be send to the server and the server will then send out messages to dedicated persons emergency contacts for this I need a free sms gateway or a rest api.</p>
  
  <p>I only need to send messages.</p>
  
  <p>Is GCM suitable?If not please suggest free gateways/api</p>