Using a one-time password to enable iOS app

Question

I am creating an iPhone app that will be free with the purchase of a set of headphones. The idea at this point is that a passcode will be included with the headphones that will let the user enable the app which is a DSP app with filter settings specifically for the headphones. The passcode only needs to be entered once and then the app will be permanently enabled. I assume that I will have to use my own server to check the passcode and return an authorization to the device. Does anyone have any advice on how to implement this functionality?

Answer 1

You could easily/quickly implement this feature using one of the PaaS (Platform as a Service) providers out there. Parse, StackMob, Azure, etc. They provide the database in the cloud and the REST API to access it, and you simply make a read on the password table to see if the entry exists (using the provider API). These services are very inexpensive and you could use the free tier until you get meaningful volume.

However, note my previous comment, that this would not be approved as an app for violating the App Store Guidelines.

Apps that arbitrarily restrict which users may use the App, such as by location or carrier, may be rejected

Apps that unlock or enable additional features or functionality with mechanisms other than the App Store will be rejected