What are some alternatives?
When comparing Storybird and oStorybook, you can also consider the following products
Storyboard That - Storyboard That is the world's best online storyboard creator.
Manuskript - Open-source tool for writers.
My Storybook - Make children's storybooks online for free.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Fanfiction.net - The most popular fan fiction website in the world according to Wikipedia
bibisco - bibisco is a novel writing software.