I don't aggre on programming not helping the very poor people, just as some examples:

Just scrapping a website that contains all the free charities in my area to put it in a single page to print.

Getting little jobs on freelancer-programmers-marketplace such as "elance"

Creating a blog where he writes tips about how to survive with extremely low income and sharing tips about it in the comment section.

Helping out other poor people to have a better grasp of technology so they can use it to improve even just a little bit of their quality of life.

Plus; the very-poor in America is a minority; the middle class is a bigger and where learning to code can be more useful.