Obsidian
A personal knowledge-base management system. It uses connected Markdown files and thus nice for Ideas of connected ideas such as Wiki and Zettelkasten.
Plugins
Some plugins: https://youtube.com/watch?v=X61wRmfZU8Y
The Sliding pane plugin seems nice.
Tips
If you use mac + Vim mode, the following command will enable key repeats.
defaults write md.obsidian ApplePressAndHoldEnabled -bool false