Memo.ai - Simple and elegant notes app on your Mac
Plot Factory - Online story planner, organizer, and writing application.
Better Notes - Simple notes app that ties notes together with #hashtags
World Anvil - World Anvil is a worldbuilding tool for Authors, Storytellers and worldbuilding lovers.
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.