Excellent and super useful plug-in that I've used for years. It just got better as the developer greatly reduced required browser permissions.

Works on gmail for what I need: links, formatting, code blocks, lists and bullets

This no longer works with LaTeX, which is a shame.

Works ok but causes random crashes when used with Webpage Sidebar extension.

This extension just _saved my life._ My brain has apparently shifted to typing **everything** in Markdown. Now I can even use my latent TeX knowledge $\forall x \in X, \quad \exists y \leq \epsilon$. And then a quick Ctrl+Alt+M and, _hey presto_, everything is beautiful[^1] and all is right with the world. And it works in any website that allows "rich editing", not just in email!

Unfortunately, it turns out addons.mozilla.org only allows plain text reviews. Ah well, you'll just have to try it out on your own to see how great this extension is.

[^1]: Almost all. Apparently I'm used to Github Flavored Markdown which allows for footnotes, but Markdown Here does not yet support them.

Does what it is supposed to do. Helps with my mails. Back and forth conversion has its limits, but that is due to the limited but easy markdown format.

Ótimo! Vai facilitar muito minha vida

This was great when it worked, and sometimes it still works. But it's very unreliable and often just fails to work.

Works like a charm :-)

Would be even cooler if it allowed dedenting a bulleted item in gmail to a level left of where it started. For some reason you can only go rightward, or else the bullet disappears.

Good, but flawed. For some reason using this messes with my line spacings. If I have a new line between two paragraphs, it sticks them together instead. Not very usable for me.

Math mode simple does not work and deletes anything between your dollar signs.

Можно использовать не во всех полях текстового ввода, но строго в определенных. В моем случае я получил "The selected field is not valid for Markdown rendering. Please use a rich editor". Mozilla Firefox 89.0b7 (64-bit).