My mapping at DebateGraph has been mostly around health, from people to planet.
DebateGraph is free-to-use: "To change the world you need to look at it in a different way."
From the Views menu: Try Bubble Focus View on a lap/desktop, Outline View on a tablet or lap/desktop for quick navigation, Page View on a 'phone. Or go direct: Outline View: debategraph.org/paulov. Page View: debategraph.org/paulpv.
"Paul is a visionary, an expert DebateGrapher, and a world leader in knowledge mapping for the common good." -- David Price, co-founder, DebateGraph, September, 2015.