WriteNext - The writing application that boosts your writing. Increase focus and writing performance and reduce distractions by separating your creative writing from other activities. Let writing be the only activity you perform in the writing application.
Freeplane - Freeplane is a powerful and free software for building mind maps.
Stashany - Online notepad for developers
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.
Calmly Writer - Distraction-free text editor for Mac, Windows, Linux and ChromeOS.
Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.