Duplicity is a commandline program to backup your files to a local folder or remote server. It is extremely efficient, using rsync to store only the parts of files that have changed while still allowing you to restore files as at any date.
It supports storing your files on a large number of backends, including Amazon Drive, Azure, Dropbox, Google Docs, Google Drive, IMAP, Mega, OneDrive, rsync, SSH, Swift and WebDAV. The backup archives are encrypted and signed using GnuPG, protecting them from unauthorised access or modification.
For a graphical interface to Duplicity, see: https://snapcraft.io/deja-dup