Homeless ppl dont even have phones dude...
but they can hold onto a piece of paper. and use a library or jobcentre computer.
the real problem is not technology but ability to convert bitcoin into fiat. (online exchanges need bank accounts and ID / residence checks)
i think a 'foodbank'/cafe/meetup service that accept bitcoin would be better strategy so that the homeless that have been given a paperwallet have a place to go to to use it.