Freeplane - Freeplane is a powerful and free software for building mind maps.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.
Sketch - Professional digital design for Mac.
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.
Invision - Prototyping and collaboration for design teams