In my Mac's System Preferences for iCloud, iCloud Drive has an Options button next to it. Clicking that shows a list of apps below a statement "Apps which can store documents and data in iCloud will appear here." Most are Apple apps like Mail, Calendar, and other Apple apps. And I understand why I would want to turn them on or off. There are also 2 or 3 third party apps as well, like my Calendar replacement, a PDF editing app, and a graphics app that can share files between my Macs so I can edit images anywhere.
But Dropbox is listed here too. Can anyone tell me WHY it is here and WHAT it reads/writes to iCloud? There is nothing in the iCloud Drive that is obviously Dropbox related, and no items that are duplicated in the Dropbox folder. The iCloud Drive folder (as well as looking at them in a browser logged into iCloud) only shows folders Documents, Desktop, Downloads, Shortcuts, and those 3rd party apps. Dropbox is not one of them. Apps which appear here have to have iCloud functionality built in to them...not all installed apps appear here.
So I'm trying to understand why Dropbox has this ability built in, and what it's for. And can I turn it off, or is it syncing some Dropbox settings between my Dropbox equipped computers on the same account? Does it have something to do with syncing photos (I do not use Dropbox's feature to backup my iPhone photos)?
Below is a screenshot of Dropbox appearing in the iCloud Drive pane:
