There doesn't seem to be an option for on disk encryption. I don't want to leave my notes on dropbox or another sharing service in plain text - something that Laverrna has baked in. I just wish Laverna was as polished as this app.
One of the major features of this application seems to be it's transparent, documented, and presumably stable data format. This makes it practical to run it on top of an external encryption layer. Safe[0] seems to be a good free encryption system that works on Mac and would be compatible with dropbox's synchronization system.
It might seem ugly to factor out the encryption like this, but even though it requires a little configuration, it's an example of elegant software composition. Its also good from a security perspective relative to every little notebook application containing its own encryption system.