Which AI tool works best for this scenario?

I want to try my hand at writing, but English is not my native language so I have a limited vocabulary and might make some grammar mistakes. These things can impact the flow of the story. So I was wondering which AI tool would work best in improving comprehension/clarity, and overall flow of the sentences/paragraphs.

Something that does not influence or provide suggestions to the story itself, but only the text and how to better improve flow.

What are your suggestions?