Really like Quiver (not affiliated at all), more than enough bells-n-whistles for me : - Everything is stored as JSON so I keep sync'ed over Dropbox and version

Really like Quiver (not affiliated at all), more than enough bells-n-whistles for me : - Everything is stored as JSON so I keep sync'ed over Dropbox and version-controller via Git. - Supports both a nesting hierarchy and tagging. - Though I don't use it much I like the JS flowchart and sequence-diagrams - etc etc