Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.
Plot Factory - Online story planner, organizer, and writing application.
Xmind - Xmind is a brainstorming and mind mapping application.
World Anvil - World Anvil is a worldbuilding tool for Authors, Storytellers and worldbuilding lovers.
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.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.