Hi...
Had you already checked excellent  Celtx  ... ?  free software for write story ( screenplay , stage play , novel , comic ) & making storyboard

It has everything you need to take your story from concept to production. Celtx replaces 'paper, pen & binder' pre-production with a digital approach that's more complete, simpler to work with, and easier to share. And its Free !!

I think I have heard about it before but I've never actually used it.

nemirc
Renderosity Magazine Staff Writer
https://renderositymagazine.com/users/nemirc
https://about.me/aris3d/