Your idea is great and well thought out. I have similar questions as other contributors but also have some suggestions.
-Could the app also be web based? Maybe this could solve the problem of some rural users not having access to smart phones, they can use a community computer and use a login to check their prescriptions, the availability of their drugs and the arrival times, could include a calendar of drop off dates and what's being dropped off when, maybe it could include a communication interface between them and their pharmacist if they have any questions? - via tracking of users, instead of drivers going directly to every customer, could you create pick up locations that are close to clusters of users? I don't know the spread of these rural users but from a scheduling and timing standpoint for your drivers, it may be more economical to do it this way (although maybe the RADUs are addressing this, pass over if that's the case) - Concern about the drivers being trusted could be solved with a portable version of the locked pill carts that hospitals use. A locked device with a password that only the patient has that changes at every pick up. When it's their delivery day or when they check in, they're given their passcode and the driver can enter it and give the medications to the correct person.