Comment Re:Is there an open-source alternative? (Score 1) 69
git-annex (and git-annex assistant for those that don't like CLI):
https://git-annex.branchable.com/assistant/
https://git-annex.branchable.com/
does lots more than just sync you files, and can do that with proper encryption (GPG) to a load of cloud providers, or to your own servers, or without needing a server at all. I could go on, but it would be better to just follow the links.