title: How to detect if same user signin from another android device?
body: <p>If I install whatup on a different device with same phone number, the old device's whats app does not work. Similar to that, in flutter App, I want to know if a user has signed up on new device while leaving signed on another device.</p>
  <p>There is <a href="https://stackoverflow.com/questions/14724949/how-to-detect-another-android-device">solution</a> proposed,but what about if there is no phone number or permission not granted</p>
  <p>another <a href="https://stackoverflow.com/questions/40887882/android-how-to-detect-same-user-from-multiple-devices">solution</a> is about token, but token change as <a href="https://stackoverflow.com/questions/37678248/in-what-period-does-the-firebases-app-token-changes-and-how-to-manage-it">mentioned</a>, so the best could be invalidate the session, but I could not find how to invalidate the session.</p>