The app should hold, and paper should back up: this + both other modules, Where There Is No Doctor/Dentist, a regional plant guide, knots (bowline, taut-line, trucker's hitch, square — learn 6), map & compass basics, your area's flood/fire/seismic maps, manuals for every device you own, and the family plan card. Then teach it — the spouse who can also purify water, the kid who can also light the rocket stove, the neighbour who also knows the radio channel. Redundancy in people, not just gear, is the final layer of protection.
The knowledge vault
Back up the whole plan on paper, then teach it. Redundancy in people matters as much as gear.