There is for Chrome and Firefox single extension, it's very convenient. Author answers the tickets

This app is a lifesaver for those of us who take notes which then proceed to be useless because, when we end up needing them, we will have forgotten that we took notes in the first place.

Bit of a bummer that auto pop-ups are not working on Firefox at the moment, but hopefully that will be implemented down the line.

I use this extension to add reminders to certain websites (e.g. "don't forget about Delta flight credit!" on Google Flights) and to add metadata that Goodreads and Letterboxd don't easily support (e.g. "recommended by Joseph, he loved the final chapter").

It's great, thanks!

Hey, thanks for adding this extension to Firefox! I found this through a mention on a Reddit thread, and the person at the time (a couple years ago) was lamenting the fact that an extension like this wasn't available for Firefox (RIP Firefox Notes), but then I searched and saw that you ported it, so thank you! Always great to see extension developers remember that Firefox exists and is used.