While trying to "solve" this problem for cheat sheets I create at my own university, I ended up with this:

https://github.com/CiriousJoker/MaterialSummaries/

(Use Google translate)

Basically, it's a set of design guidelines and a template that I use that many people liked (I'd guess 70% of students use my cheatsheets).

However, commercializing something like this would essentially mean rebuilding a subset of Google Docs so I guess that won't happen anytime soon