I kept signing in this dumb Grammarly, but it keeps making me sign in over and over again and it couldn't work properly.

I loved it on the desktop but it doesn't work on Firefox for Android

Sometimes it interferes with some websites. Eg Microsoft Technet forums and it's a pain in the ass!

The *only way* is to open Menu > Add-ons > select this add-on > Disable it (temporarily)

It would be nice if there's a right-click shortcut to disable it temporarily.