title: How can I transfer data from android to a PC via the Internet (kind of push notifications)
body: <p>This is what I want to achieve:</p>
  
  <p>I have an android phone app (native) and a desktop PC application (Delphi) that "know" each other 
  (that means somehow they have been initialialized to know each others globally unique ids). 
  If I do a specific action on the phone, I want to transmit data (some bytes to several kB) from the phone to the PC via the Internet. (Using an external server / service for this is OK.)</p>
  
  <p>Constraints:</p>
  
  <ol>
  <li>phone or PC could be anywhere in the internet, eg behind a
  NAT-Router and/or behind a firewall </li>
  <li>there should be no configuration necessary by the customer (despite the setup of the unique ids). It should work out of the box.</li>
  <li>start of data transfer should be fast (preferably &lt; 1 sec) </li>
  <li>potentially there will be several thousand users that will use the service </li>
  <li>I would prefer to not rely on a google account (this is not a deal breaker)</li>
  </ol>
  
  <p>First idea was to setup a REST service, to which the phone would send data and which the desktop application 
  would be polling. But that does not seem to be elegant and I have some concerns about how this scales. Any other ideas?</p>
  
  <p><strong>Edit:</strong> The final program should be something like a remote control for the Windows application. So something like Google Cloud Messaging for Windows would help (but from MS this seems only to be <a href="http://msdn.microsoft.com/en-us/library/windows/apps/dn263236.aspx" rel="nofollow">available for Metro apps</a>).</p>