Storybook describes itself as “a free, open source novel-writing tool for creative writers, novelists and authors which will help you to keep an overview of multiple plot-lines while writing books, novels or other written works. Storybook assists you in structuring your book”.

Here is a screenshot:

Main Window of Storybook

It offers a lot of more features than I can describe, so better look at the homepage. You can get it from my OBS repository (package storybook).

Have fun and write lots of good stories!