What are some alternatives?
When comparing Storybird and Fanfiction.net, you can also consider the following products
My Storybook - Make children's storybooks online for free.
Wattpad - Wattpad is now the worlds most popular ebook community where readers and writers discover, share...
Storyboard That - Storyboard That is the world's best online storyboard creator.
Cowbird - Cowbird is a simple tool for telling stories, and a public library of human experience.
Archive of Our Own - An Archive of Our Own, a project of the Organization for Transformative Works
Little Bird Tales - Little Bird Tales: Capture the Voice of Childhood.