At the very bottom of the Sync page, press the Dropbox Sync button.
- Sign into your Dropbox account (it will open a dropbox signin window)
iOS ONLY (Dropbox not available for Android) - SAVE or RESTORE your log (it’s like server sync). SAVE will create a new folder in your own Dropbox.
Dropbox is used also to import your old logbook data : see Import your Log.