You could also use plain markdown files, any free Markdown editor/IDE, and git, and sync with a remote Git repo using gcrypt for encryption (git-remote-gcrypt).

You could also use plain markdown files, any free Markdown editor/IDE, and git, and sync with a remote Git repo using gcrypt for encryption (git-remote-gcrypt). It's just a bit of a pain to set up, and also, not mobile-friendly.