Plot Factory - Online story planner, organizer, and writing application.
Freeplane - Freeplane is a powerful and free software for building mind maps.
World Anvil - World Anvil is a worldbuilding tool for Authors, Storytellers and worldbuilding lovers.
Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
SuperNotecard - Introducing SuperNotecard. SuperNotecard is an online writing tool that features virtual notecards to help arrange facts or scenes, track details, organize paragraphs, and clarify your composition process.