Cyberduck | Libre server and cloud storage browser for Mac and Windows with support for FTP, SFTP, WebDAV, Amazon S3, OpenStack Swift, Backblaze B2, Microsoft Azure & OneDrive, Google Drive and Dropbox
Create Network Drive to Access Files on Dropbox, Google Docs, FTP & More | SumTips
How to Easily Achieve Dropbox to FTP Sync for Free