[tryptophan]

The best I have found is "Duplicati" which runs in the background of your computer and can backup to all internet backends(I use it with ondrive and box), a NAS, or a USB stick/attached drive(pretty much anything). It is open source as well! It automatically (locally) encrypts all your files after compression and does it in blocks, making it quite space efficient. It also has versioning. https://www.duplicati.com/