With the number of troubleshooting docs and support people that have users clear their cache as a troubleshooting step, this terrifies me:

"Data is stored in the persistent memory of the browser you use to install OpenNotas. Therefore, data is only lost when you clear the cache or uninstall the OpenNotas app or the browser. I recommend you use the sync feature or back up your data regularly to avoid unfortunate situations."

Your main page links here when clicking for info on the sync feature:

https://docs.opennotas.io/advanced/sync-flow

This will probably scare of any casual user, and doesn't tell the user how to set it up.

I'm thinking it should probably link here:

https://docs.opennotas.io/started/setup-sync/

"OpenNotas currently supports several data storage services."

Listing out which services are supported, would be useful. This kind of information will dictate if I would bother to try the service or not.

Not wanting to rely on browser data, and not having information up front on where data would be backed up, makes me not want to try it. I could be a weirdo, but that's the path I took while looking at this.