Timothy,
We feel and support your cause, don't despair. Vulnerable people are
everywhere.
This mailing list just probably won't help much with your agenda. A
political platform is probably best, of which this mailing list is far from
it.
Your use case is less about Schema.org and more about thinking how a
homeless person might use some service or kiosk to find a public toilet.
It probably wouldn't be their cell phone, which doubtful they would have in
their pockets, but they might. Even further away from reality would be
them carrying a laptop to use a browser.
I more likely scenario that would help those vulnerable and unfortunate
would be public kiosks that could run those Apps or a locked down browser
pointing to an OpenStreet maps layer of public toilet data or any other
data.
My advice is to spend your energy towards something like that and drive
your agenda in social spaces and politicians front doors.
All the best,
Thad
+ThadGuidry <https://www.google.com/+ThadGuidry>