@kelton: Check out FolderSync. It can do just what you're asking for:
https://forums.androidcentral.com/e....tacit.android.foldersync.full&token=4DYWgi5Y
I use cloud services extensively for 2 businesses and our personal stuff. I currently use mobile apps and desktop clients for Google Drive, Dropbox and Insync plus Cloud HQ sync services.
I need to keep 2 phones, 2 tablets and 2 PCs, 1 Linux and 1 Win 7, all backed up and everything synced. 5 email accounts, 4 contact lists, documents, photos, calendars, etc etc. And I don't feel backups are truly complete unless they are saved to multiple locations.
That's a lot of work to do manually, plus manual backups can miss the most recent changes or additions. So I've automated most of it. Multiple backups at multiple locations are created in real time.
All email accounts are IMAP so mail stays in the cloud as well as on devices. Google stuff is backed up to Google accounts. Photos taken on phones are automatically immediately uploaded to Google Drive using FolderSync. Backups created on devices for apps like AquaMail or Nova Launcher are also immediately uploaded by FolderSync. A few odds and ends are manually backed up and sent to the appropriate Google Drive storage for that account.
We have 5 Google accounts. One Google account has 1TB storage on Google Drive which is included with our Google Fiber service. That serves as a kinda master storage depot. A free 10GB Dropbox account is used to backup our most critical business and personal files.
Cloud HQ service is used to sync the Dropbox and other 4 Google Drive accounts to the master Google Drive in real time. Insync is used to keep everything on the master Google Drive storage synced to local storage on the Linux PC and the Google Drive desktop client handles that chore for the Win 7 PC. Dropbox clients on both PCs also sync Dropbox locally separately.
On the mobile devices Google Drive and Dropbox apps or FX File Explorer make everything available tap-tap easy without taking up storage space. FolderSync also handles sync of a few things to the mobiles, as well as instant photo uploads to Google Drive.
What all this means is, as I said, we always have backups to multiple locations, both cloud and local. And it's mostly automatic and done in real time. It took some thought and time to setup, but once done files sync around everywhere with no effort required.
Some people are paranoid about cloud storage but I don't know how I could accomplish such thorough data redundancy, security and easy access from anywhere and any platform without it. And it's automatic!
Our house, which includes our home offices, personal records and records for 2 businesses, could burn down and we wouldn't lose any important records, photos or saved music.
Android since v1.0. Linux user since 2001.