This is one of the best tools which guides you to correct each and every Letter you write. Yes, it works in MS-Word, Outlook Email, Gmail, and the ultimate is when you use your whats app web as well.
For the beginners who don't know the grammar, vocablury this is the best way to correct their mistakes & learn.
Suggested to my colleagues and their language in communication has improved a lot and all wonder how this has happened in short time.