At Tooltivity.com, we manually test productivity browser extensions and provide honest and detailed reviews.

Grammarly received an impressive rating of 8.8 in our tests. We evaluated it based on features, design, ease of use, security & privacy, value for money, and performance. You can find the full test report here: tooltivity.com/extensions/grammarly

Grammarly (Spellcheck flags the name "Grammarly" as being misspelled, the irony in that is too much!) I left 4-stars a few months ago, but my review did not get printed for whatever reason, probably due to all of my misspelled words. Actually, it is a pretty good little program, easy to use, not complicated or confusing, and the cost is very reasonable. Take advantage of the FREE trial of the PRO version and you will see in a few days if it is going to work for you.

It condenses my words to be more accurate and understandable.

I am sure this app works great, but it is not what I want because it will not correct my spelling with out purchasing an upgrade.

does not work on firefox at all

Can't do spell check anymore, needs Premium. But getting a lot of features, which may Improve the writing, but looked behind a paywall.
Now it only shows me, that I have done something wrong, but doesn't show me that.
For a non English Native, it helped me a year prior, but not anymore.