As good as this extension might be, it appears to not respect the font setting outside of headings. Additionally it seems to have performance issues on larger article.
Example sites: settheory.net, plato.stanford.edu

Only been using this for a few hours, but finding it useful for saving recipes to Evernote. Recipe sites tend to be cluttered with shopping lists or recommended recipes, reviews, and such. But Evernote's built-in "simplified article" clipping mode often removes the featured photo of a recipe along with everything else, which I don't want (Firefox's built-in readability mode often does too). Tranquility (+ uBlock Origin's block element feature) gets rid of most of the junk on sites like Food Network but gives you the option to always keep pictures, so I use Tranquility and then clip to Evernote, which works nicely.

It's also nice that on the many recipes where Food Network annoyingly has only a video rather than a photo, Tranquility hides the video and automatically uses the preview image from the video instead which is exactly what I want and was having to do manually before!

Icon looks weird but app works fine

This is a great customisable reader app which - unlike the firefox native version - allows you to keep images in and hyperlinks highlighted.

The options are a bit clunky - and the default view in my opinion should be with a sans serif font (not Georgia) because this is usually better for readability and accessibility

Thanks to the dev

I'm using this from Fennec Android. Please optimize the experience in mobile phones. I CAN'T SAVE PDF IN ANDROID BROWSER. The PDF option isn't working. Please fix this Arunk.

works pretty well but, would love if options were user friendly