Okay first I'll just mention the tiny issues I have:
1) I keep getting ["Error saving — please copy your work to a safe place."] ... now this doesn't effect me since I only use this as a testing zone but it could become a problem later on if I do use it for actual documents.
2) This isn't really a big deal but I can barely hear the typewriter sound effects! D:

Okay now the reasons why I LOVE this add-on:
I was literally just looking for a markdown editor but as an extension, and for some reason I couldn't find one — until now!! Love it. The UI is great. The UX is intuitive. The cheat sheet is so helpful. Idk if this is universal to Firefox or the add-on itself but I'm so grateful clicking the icon opens in a new tab haha. .. I don't have any real problems with it since it satisfies my needs (again I just needed a wysiwyg testing zone), so all the other features are a plus for me especially the "chaos" ones :D

All I can say is 'Thank You'!

Markdown Editor will show you a WYSIWYG preview of simple Markdown as you type. But it has a lot of limitations:

- Doesn't handle simple markdown like number lists (even though it handles tables pretty well).
- Does a poor job of rendering nested/indented lists.
- Its own default "Welcome to Markdown Editor" document has "An indented bullet" that doesn't indent!
- You can't simply open a local or remote .md file in Firefox and get Markdown Editor to preview it, you have to open the extension and copy and paste the markdown into it. (To be fair, last time I looked into it a decade ago, Firefox made it really hard for an extension to handle rendering a MIME type within Firefox.)
- It wants to manage its own set of markdown documents... somewhere, and then you can export these (only to your Downloads folder). I already have .md files all over my file system, I don't want to manage another set within a Firefox extension.

I had high hopes, but for many users it would be less hassle to write .md files as GitHub gists.

Bullets don't seem to work. So I looked for a help page. There is a "Help" menu/button, but it only opens the www.coffeeandfun.com/support page, where there is no help or support information at all. Only a "Visit Chrome store" button. Disappointing.

Tried to direct browser to local .md file; however, it didn't work; hence, I was unable to edit my local .md file.

Very good ! It is the markdown online editor I want.

Very decent editor.

Integration with Grammarly plugin would be a killer feature.

Works great, except when the "M↓" icon is moved to the top bar (using "Customize" in the hamburger menu) with the File, Edit, View, History, Bookmarks, Tools and Help menus, it's invisible until I hover the mouse there. This is because the top bar is a bit darker than the grey area near the address bar.

It's pretty awesome to be able to export Markdown to HTML!

It's very perfect to write Sina's blog .