title: How I can send a file from my server to an Android app?
body: <p>I need to send a file to an Android application from my server. I have the user's IP address saved in a database from the last time he was online. </p>
  
  <p>Does Android have something like listener over the internet so I can send a request (from myserver with the IP) to check if is it the user I am looking for or if the IP has changed?</p>