Gitify - GitHub Notifications on your desktop.
Freeplane - Freeplane is a powerful and free software for building mind maps.
Meteorite - Smarter GitHub notifications.
vym - VYM (View Your Mind) is a tool to generate and manipulate maps which show your thoughts.
Neat.run - Neat puts SaaS notifications in your menu bar. Streamline your code review and ship with ease. Preview, triage, and jump to issues in one click or keystroke.
Linked Ideas - A macOS/iOS apps to treat ideas as links of concepts.