Firefox comes with a handy SYNC feature that allows users to synchronize Bookmarks, Preferences, Passwords, History and Tabs between devices across different platforms.
However, the sync action only triggers every 60-minute and there is no user-configurable option provided. Although one can put a Sync icon onto the toolbar for easier access, it is still far from practical needs.
To unlock this limitation, do the following:
1) Type “about:config” at the address bar
2) Search for “services.sync.syncInterval”
3) Change the value from 3600000 (milliseconds = 3600 seconds = 60 minutes) to any value (in millisecond) of your choice
4) Close and restart Firefox
The Sync action will now trigger at the interval you just set.