The UstadMobile app claims to be AGPL licensed, but this page says
it can only be used "free of charge" by individuals and organizations
with less than 500 users:
Such a restriction is incompatible with the AGPL license.
I looked for documentation on the wireless protocol or even on how to
run the application, and didn't find anything. For example, is the
protocol compatible with Apple's 10-year-old AirDrop protocol, which has
been reverse-engineered? If not, why not?
It looks from outside like the app needs to be customized for every
different collection of data that people might want to share offline.
Why would anybody build an app like that, as opposed to a general
purpose offline file sharing app? It would be like having a web browser
that can only connect you to one website...