title: How to store data on the server permanently without the user having to register
body: <p>I am currently developing an app with Flutter, which is similar in principle to the app &quot;Celebrate&quot;. In this app I need to be able to store certain data on the server permanently without the user having to register. How can this be realised?</p>
  <p><strong>Example:</strong></p>
  <blockquote>
  <ol>
  <li>the user starts the app and creates an album</li>
  <li>the user deletes the app</li>
  <li>the user reinstalls the app</li>
  <li>the previously created album is still there</li>
  </ol>
  </blockquote>
  <p>I have thought about two possible variants. Which variant is the one I should prefer?</p>
  <ol>
  <li><p>when the user starts the app, I store unique device information in the database on the server. So I always know to which device the corresponding data can be assigned. Does Apple even allow me to retrieve and store device information? Would this be a good solution?</p>
  </li>
  <li><p>I see that Firebase offers &quot;Anonymous auth&quot;. Does that happen to do exactly what I need? In &quot;Celebrate&quot; it is so that even if you reinstall the app, the data will probably still be retrieved. So there is nothing stored locally. Could the developers of Celebrate use this or similar methods?</p>
  </li>
  </ol>
  <p>Thank you for a competent answer!</p>