LanguageTool
I have found an excellent plugin for Mozilla Firefox that helps users check entered text for grammar, spelling errors as well as assisting with paraphrasing text.
LanguageTool is free and can be installed from within the browser extensions tool.
This plug in can work with a very large number of websites and helps me ensure that my posts are as error free as possible.
So when typing, the tool monitors your text for errors, flags these up and allows you to click and make changes. It can also spot errors in grammar, such as not using correct punctuation. It's an excellent tool.
The above paragraph was typed with the help of the tool. The video below illustrates how it can be used.
Langtool also seems to integrate and work with Overleaf, the online LaTeX editor really nicely.