Just ran across something called Odrive. If you’re anything like me, you have multiple storage devices, not to mention all the online accounts. I haven’t tried this yet, but it looks interesting. Plus it’s still in beta testing so everything is free. At some point there will be paid features.
According to TechCrunch:
Odrive currently integrates with Dropbox, Facebook, Instagram, Google Drive, Gmail, and Microsoft OneDrive. Some of those services, including Google Drive and Dropbox, allow two-way sync, so you can update files and save new ones directly from odrive.