As of this writing (November 2021), NarraFirma has been in use for several years – not by a million people, but enough to have grown and matured.
However, we still suggest that you back up your work every so often by exporting your project to a JSON file (go to Project administration and choose Export). We also strongly suggest that you set up SSL security on any web site that runs NarraFirma (unless you run it locally).