Well this would be for studying at leisure, not use during a fight itself, so a mobile app is not necessary. So these are interesting ideas, thanks.

Dr Andus wrote:

I was going to recommend a concept mapper such as VUE or CmapTools, but
they're not cross-platform, and I imagine in a life-or-death combat
situation, such as a street fight, having a mobile iOS or Android app
with a powerful search function would be critical.