productboard - Beautiful and powerful product management.

Plot Factory - Online story planner, organizer, and writing application.

Aha - Aha! is the new way to create visual product roadmaps. Web-based product management tools and roadmapping software for agile product managers.

World Anvil - World Anvil is a worldbuilding tool for Authors, Storytellers and worldbuilding lovers.

ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.

Scrivener - Scrivener is a content-generation tool for composing and structuring documents.