Most of the time (+90%) the search for definition with the double click does not work.

Constantly finding it doesn't actually make the corrections. Or at times it appears to have done so, and once the text input has been sent, you find that it hasn't, or after five to ten seconds, every edit is reverted back to the original state.
Either this is deliberate to get you to pay for the software, or it's a sign of a terrible service.

I've been stuck with a "Grammarly is active, but key features are missing" message for months, despite the fact that I'm logged in. I've switched to just using the less convenient desktop app since this extension is unusable in its current form.

It was working great but now it doesn't save my preferences and is always turned on on all website which made it very unusable. Such a shame.

It was brilliant. but somehow it got uninstalled and I have spent three days trying to reinstall it. It's shit.

Sucks at doing anything. Buggy mess that peddles a worthless premium offering.

Does not work at all. Tried different sites misspelled words clicked, double-clicked. nothing like you show happens.

Re-installed but unfortunately didn't still work

firefox add-on login doesn't work!!!

It asks me to login but never lets me login.

Does not work... It says "Grammarly is active, but key features are missing" I cleared cookies, all datas, re-installed plugin, ... always same with macOS 11.0.1 - Firefox 84.0.2, That's really annoying for this such a cool thing.

I am not being able log into the Grammarly account in the add-on, in Firefox.

Doesn't work whatsoever.

Not working. Latest Firefox on Mac.

This extension on Firefox behaves erratically. Meaning, I typically have to go into Markdown Mode for Grammarly suggestions and corrections to "stick" to my postings. The Grammarly extension used with Google Chrome works without issue. I wish this extension installed with Firefox worked the same.

Garbage. Doesn't know grammar. Stupid suggestions. And buggy as fuck.

good but expensive.

Didn't work at all...

Badly-written 36 MB addon which stops working after it is disabled and re-enabled, requiring reinstall. The company has very aggressive marketing and forces people to install this addon. In contrast, Linguix grammar checker works online without any addon. This addon integrates everywhere, thus sending anything what is typed to Grammarly. They don't care if it contains sensitive info.