Finally found this one working well in latest firefox 68. I'll continue to try it these days.
Thank you for your great job!

Great add-on!
If you cant open yout `.md` file on linux,
see this [question](https://superuser.com/questions/696361/how-to-get-the-markdown-viewer-addon-of-firefox-to-work-on-linux) .

Works for me.

On Linux, it required this manipulation with MIME database: https://superuser.com/a/1175837/60553

Install it and without having to configure anything your makdown file is rendered in Firefox's window!
Easy peasy ...

Simple and powerful. Latex Math support works pretty well.

Good, but doesn't correctly render code blocks for python

Prise en charge d'unicode !

Just add this add-on to FF and everything works fine. Thank you for developing this tool.

works great :)

Simple and best markdown renderer.