for the server: my first thought is to continue using your existing FTP server. If you want to restrict access, just make a username for everybody, and make app

for the server: my first thought is to continue using your existing FTP server. If you want to restrict access, just make a username for everybody, and make app users log in to start. I haven't looked into it, but I'm pretty sure I could get a decent FTP or SFTP client going on iOS, using existing libraries. And yes, there may be a mapping solution that would make this possible, but I haven't looked into it. I have used the existing MapKit framework, though. It's good for what it is, but it's also notoriously resistant to doing anything unusual, like adding your own map tiles. If you need to do that, then you typically must discard MapKit altogether and go with something else. We should probably take this offline after this. My email address is in my profile.