I am starting a small photobooth company which allows people to hire our photobooths for special occasions.
The photobooth will automatically upload the photos that were taken in real time to a server. The iPhone app will access the server and people will be able to view the photos in real time (and will need a password to access) and can download their photo(s) onto their iPhone and the app would have an option of editing the photo just like Instagram and whatnot.
The people who download the app, will need to register, with their emails and username. They will need to sign in to access the photo gallery.