Do these homeless people have access to mobile phones for this mobile app? I'm sure the service means well and does a great deal for those who do have access. It seems like the infrastructure issue of homelessness seems like a better target for this end all be all solution for technology to solve everything.
Perhaps I'm painting a different picture of someone who is homeless than this app is targeting. In a temporary homeless situation I suppose I could see this working...? Going down the list though I can't say that this app really has that in mind.
Apparently research from Sydney University shows "95% of people experiencing homelessness have a mobile phone" however this doesn't guarantee access to the app and related services. (Source)
I totally agree there is a need for a wholistic approach to the problem and I don't think the app or it's creators are preaching any form of technological solutionism. This app is one piece of a much larger puzzle and in my opinion helps highlight other parts of the infrastructure which need more resources.