Fabulous! This is a much appreciated and good replacement for the ditched rss-feed function on firefox 64.
I'm pleased with the slender layout in a sidebar.
May I add some suggestions:
- It would be great if we could rename the rss-feed entry (comes sometimes generic...)
- It would be a luxury if we could move the entries as we wish up and down
Thank you very much and I do wish you will continue your invaluable work. Looking forward to any developments. Cheers!

First of all, thank you for picking up the baton on a Sage replacement!

A little feedback:
The addon doesn't handle feeds in sub folders like Sage used to. I have hundreds of feeds saved and having them all in one giant list is not an option.
In Sage, clicking the feed title would show the contents of the feed that was displayed using a user editable CSS stylesheet. This was really useful for setting your own layout, text sizes etc.

Looking forward to seeing this addon improve.