pybackups (or Backups) is a simple gui tool (command-line variant will be possible in the future, if there’s interest) for doing backups.
The usual use-case will be to perform a backup from a given set of source directories to a destination directory, which is generated based on the current date. A full backup is taken every day, and files are stored without encryption in the destination, and is browsable by any file explorer/terminal without the need for any applications.
Its still very much a work-in-progress, but feature requests are still welcome.