Assuming one has a small solar module or other means to charge his/her phone of course.
I know of the "Offline Survival Manual" from ligi and some First Aid apps. But are there any reliable apps for creating mesh networks for communication in case networks are down?
In the event of a worldwide, cataclysmic event, probably the first thing that'll go is the Internet and electronic devices. Not immediately but within a couple weeks.
The best thing is to rely on things that don't need an Internet connection. Morse code might be worth learning because it requires the smallest medium to send a message.
The emergency alerts on broadcast TV and radio wouldn't reach most people today, so it's worthwhile to have the emergency alert apps from such organizations as the Red Cross, FEMA, and CodeRED; and possibly your local newspapers and TV stations. I live near a nuclear power plant, so I am also subscribed to a local grassroots organization that monitors it. Some organizations also have SMS alerts, which might work when the general internet doesn't.
Broadcast radio is still important though, so if your phone supports it, get a real radio tuner app. Nextradio works for fm radio. Since these use your headphone cable as the antenna, one feature to look for is the option to play audio through the speaker despite the headphone being plugged in.
I'd be interested in any radio apps that work for other bands. There are many that claim to receive NOAA radio, police radios etc. but AFAIK they are all internet streams. (Still worth checking out ahead of time.)
I'd say physical fitness: the ability to lift things, pull one's own weight (not bench press an equivalent mass, but actually pull one's body over obstacles): chin ups or equivalent. Jump, grab wall, pull body over wall, get to the other side.
The ability to run fast for a period of time. The ability to run at moderate speed for an extended period of time. The ability to walk for a long period of time. (real life situation: noWhether we like it or not, if we don't have these we're more like a burden and rely upon those who love us to survive.Whether we like it or not, if we don't have these we're more like a burden and rely upon those who love us to survive. transportation and no comms, shrug it and walk 20 miles during the night to get home).
The ability to lift someone and walk/run with them.
The ability not to eat for extended periods of time without panicking or going insane (i.e: not needing to eat every couple of hours, or three meals a day or becoming intolerable). Does help to have gone a day or two without eating before just to know one can do it.
Basic self defense (hand to hand).
Knowing how to handle firearms helps (safety, clean, disassemble, reassemble). Shooting right helps.
"Survival stuff" (ability to make fishing instruments with basic items, traps, etc. Ability to skin animals helps). Being handy and resourceful in general (good with hands, manufacturing things and tools, fixing stuff).
Having stashed or acquired valuable things to use to buy things or barter.
Mental resilience, morale control, positivity and determination, and the ability to radiate this onto others help tremendously.
In the absense of these, we are a burden and depend on those who love us, appreciate us, or just are in a good mood for our survival.
As for it's mesh features I also question how reliable (if at all) that would be in such a scenario.