title: Flutter - How to check is the app has a new version?
body: <p>I create an app with <strong><a href="https://flutter.dev" rel="noreferrer">Flutter</a></strong>. I need to force users to update the app when I upload a new version. I try <a href="https://pub.dev/packages/upgrader" rel="noreferrer">this package</a>, but I think that it doesn´t work. In the documentation, we can read that we can verify the version with this code.</p>
  
  <pre><code>Container(
       margin: EdgeInsets.fromLTRB(12.0, 0.0, 12.0, 0.0),
       child: UpgradeCard();
  )
  </code></pre>
  
  <p>The problem is: I need to check the version in *'initState', not in <strong>Scaffold</strong>. So what is the right way to check the version on the app start?</p>