I think creative writing can be exercised only in real meetings with other writers, exchanging opinions and coming up with assignments to challenge and improve your writing creativity. I doubt any software or any computer can improve someone’s writing skills. Going to a creative writing group, get an assignment, try to use your creativity, and get direct feedback from real humans, … No computer program can replace that.
The only alternative you may get is an online creative writing community, like a closed forum for members only, where you get an assignment and forum members post their writing on the forum, then the other forum members can give feedback. A sort of online alternative for the regular creative writing meetings. But at least, even if it’s via a virtual meeting place, at least you are still dealing with humans to give an assignment and then provide feedback.