NovaScriber - A most awesome tool to write novels
Novelize - Novelize is an online novel writing app designed to keep authors on track.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Manuskript - Open-source tool for writers.
SceneOne.app - Book writing software that runs in any browser. It is designed by novelists to have the tools and workflows they need yet be simple to use, and runs on every device (Windows, Mac, iPad, phones, etc).
BlankPage - Stay motivated to write, and finish your story