I've been using Whitesmoke for a while now, and it...

I've been using Whitesmoke for a while now, and it has significantly improved my writing. The grammar checker is top-notch and catches even subtle errors. The suggestions it offers are quite helpful, and I love the fact that it also checks for plagiarism. The only drawback is that it's a bit pricey, but considering the quality of the tool, it's worth it.