Go to app settings and check that you can see the new Synchronization option, with all sites listed. Update a site name or username, click the synchronize icon of the updated site and check that the data is updated. If it's the current site, check that the data is also updated on the side menu. Update the current site remote CSS styles (either change the url or update file contents). Synchronize that site and check that the new styles are applied. Check that the caches are invalidated (data is refreshed).