Honestly, if I'm trying to organize some concepts into a tree, I'll go into Word, open a blank document, and switch to Outline mode. Not the most complex solut

Honestly, if I'm trying to organize some concepts into a tree, I'll go into Word, open a blank document, and switch to Outline mode. Not the most complex solution but also super easy to use. Tab to indent, shift-tab to unindent. Select-drag-and-drop... etc.