It's pretty impressive that the units have a net cost of only $55. Looks as though it's just a repeater, connect a cell phone to a tower via the improved line of sight afforded by the balloon.
Rural cell coverage. One of my colleagues from "out-state" (as the non-Twin Cities part of Minnesota is called by us urbanites) brought this to my attention. I remember once seeing something about Al Haig leading a company that wanted to provide WiFi to cities with a tethered, or maybe stationkeeping, blimp. It seems to me that the weather makes such a system a non-99.9999% livetime system.
However, here's my $1 million idea, for emergencies, disaster-preparedness and the like, have a blimp which can manage cell-coverage (so all of the different CDMA, GSM, and other pseudo-standards in the US) and is deployable on short notice. Earthquake? It shows up over the Bay Area. Terrorist attack? Ditto. New Orleans flooding? Think we could sell the idea to Homeland Security?