Restic - Easy: Doing backups should be a frictionless process, otherwise you are tempted to skip it.

ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.

Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.

ExpanDrive - ExpanDrive is a fast network drive and browser for cloud storage.

rsync - rsync is a file transfer program for Unix systems. rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync.

FileCloud - FileCloud is an enterprise file share, sync and mobile access solution.