Without a doubt my new favorite feed readers/managers! For a long time Feed Bro was my go-to browser-integrated reader, and I still love it; it's an outstanding tool.

However, Sage-Like Feeds has a smaller memory footprint, is more compact (fitting neatly in your sidebar), which allows use while browsing (multitasking FTW!) I also like the two-frame view, allowing you to view your list of subscriptions (which can, BTW, be organized into folders and even sub-folders!) while simultaneously looking at the list of articles for a feed.

As far as customization, features and eye candy, it's just as packed as Feed Bro, or any other popular managers, and allows for quite granular customization.

Personalizing the primary and secondary theme elements is also very easy using the settings page, providing for color and typeface customization. Related to this, there is also a beautiful preview view for articles, an excellent feature if you don't feel like reading a whole article just yet, but want to quickly glance at its contents. The preview window/view is also customizable, allowing even for custom (CSS) style sheets!

The developer's attention to detail and passion for quality software craftsmanship is very evident as soon as you open the sidebar view. He/she has generously taken probably seemingly endless hours of hard design, coding, debugging and updating for the sake of us end-users and our desire to personalize and adapt the software we use to our own tastes, a developer attribute that is sadly these days forgotten in the name of providing a "minimalist", "modern" UI/UX, and I applaud the developer for this amazing, efficient and valuable tool we're able to so freely use. Thank you so very much, @arielg! o7 <3

This RSS reader add-on is really simple - a pleasure to work with. So intuitive and low bandwidth. I had Just one question regarding privacy and the developers comprehensive response (below) has bumped me up from four to a full five stars.

My concerns were: I notice several privacy permissions are required for it that pique my concern: 'Access your data for all websites', 'Download files and read and modify the browser’s download history', and 'Access browsing history'. Why is this?

Great to have this back on the newer Firefox versions, really could do with some more options for things like time to display the hover tooltip on RSS feed items its way to slow (want to be able to move the mouse over all of them and have the description tooltip show almost instantly like 100ms ~ ) and also an option to customize the tooltip colors...#

Would be great if you can add support for Vivaldi browser built in sidebar

Wow!!! Finally!!! An Sage alike addon!!! Thkx very much for the effort!!!

Nice! Version 1.8 has quite improved but still I prefer Drop Feeds as Sage++ alternative - https://addons.mozilla.org/en-US/firefox/addon/drop-feeds/ :
- super fast asynchronous feed checking;
--> script manager and security filtering:
html/css blocking - e.g. when rendering feeds no flash/media content downloaded/autoplay (unintercepted by uBlock Origin). Drop Feeds can be configured to filter out these annoying rich content;
- feed items list toolbar;
- hide read articles/feed items.

Seems like a very good replacement for Sage addon. I'll take it.