GoodSync synchronizes and backs up files such as photos, financial documents, MP3s, and e-mails between desktops, cloud services, servers, and external drives. Its innovative synchronization algorithm offers true bi-directional synchronization, while its peer-to-peer (P2P) connectivity with block level incremental data transfer allows you to enjoy even faster backups – saving you time and increasing productivity.
GoodSync utilizes AES with 256-bit key encryption, with all file blocks chained and random salt is applied.
Supported cloud storage services include:
Google Drive
Amazon Cloud Drive
Amazon S3
OneDrive/Office 365
Windows Azure
Dropbox
Backblaze B2
PS: I am using this software on Windows and Mac for many years.
Good software! I use this on my Laptop to automate backups to my PC (LAN) and Dropbox.