title: How can I sync localStorage across Chrome instances (or use chrome.storage.sync without a published extension)?
body: <p>Here is my situation: I have written a number of Chrome userscripts for my personal use. Previously, I only had one machine with one instance of Chrome on it, so I was perfectly happy to dump any persistent data into localStorage. </p>
  
  <p>However, I now have multiple machines, and want to use my userscripts on Chrome on all the machines, with my persistent data coming along for the ride. Synchronizing the userscript code itself is straightforward if a bit tedious (stick it in a Bitbucket repo, then pull and manually install), but I have no idea how to synchronize my localStorage data across machines.</p>
  
  <p>I have considered converting my userscripts to proper Chrome extensions and using the <a href="https://developer.chrome.com/extensions/storage" rel="noreferrer">chrome.storage</a> API (data stored using <a href="https://developer.chrome.com/extensions/storage#property-sync" rel="noreferrer">chrome.storage.sync</a> apparently can be sync'd if you have a Google account connected to your Chrome instances, which I do). However, here is the issue with that for my use case:</p>
  
  <ul>
  <li>In order to synchronize your data, it appears that you have to publish your extension to the Chrome store.</li>
  <li>I don't want my extensions publically viewable on the Chrome store, since 1.) that costs money; and 2.) some of the extensions are "sensitive" in nature.</li>
  <li>Even if I were to spend money and thereby solve (1.), the only way I've found to put private extensions on the Chrome store is to be using Google Apps for Work or Education (cf. <a href="https://support.google.com/chrome/a/answer/2663860?hl=en" rel="noreferrer">"Publish a private Chrome app"</a>), and I obviously don't have a personal instance of Google Apps. </li>
  </ul>
  
  <p>So: is there some way for me to either 1.) sync localStorage across machines directly, or 2.) use the chrome.storage.sync API without a publically published Chrome extension? </p>