I know in the past there have been a few that have volunteered themselves as members of the "grammar police" (not being critical here now) and many of us that have, due to our post, necessitated the need for such. I know I need as much help as I can get so when I came across this add-on for several of the current browsers (Edge, Safari, Firefox, and Chrome) called "Grammarly" I took a chance and tried it out.
Thankfully it is free, as well as there being a paid option., but I've found it particularly useful when commenting on this forum or others and it has policed me many times, mostly steering me in the right direction.
Another Plug-in or extension that I have found useful recently has been one called "Honey". I can't remember the computer website that recommended I try this one but I did try it and have found that, in my case, it actually has saved me some money. Not enough money to have a nice steak dinner at one of our local steakhouses but has saved some pocket change in the short time that I have tried it.
Website for Honey CNet's take on Honey
So if you are into checking out new and interesting extensions for your various browsers you might look into checking these out and commenting on them.