title: Ionic Notification/Push message
body: <p>I need to send a JSON containing the category and the message all users who have my application installed, like this: </p>
  
  <pre><code>{category:"shoes", message:"New pair of shoes available"}
  </code></pre>
  
  <p>then I need to <strong>display a alert/notification only to users which checked a specific option</strong> which matches the category in the JSON.</p>
  
  <p>I'm using Ionic, NodeJS and Express. How could I do that?</p>