in app purchase for free via unlock pin?

Question

Were building an app that works with some external hardware.

We would like to have some kind of in app UNLOCK mechanism whereby if a user purchases the external accessory they get a PIN code that lets them fully unlock the app.

We looked at in app purchase but it seems it would require a fee to get an in app unlock going... and we don't want to charge once the user has purchased the accessory.

Were concerned about how to go about this the 'right' way so that its not breaking any Apple App store rules.

Does anyone have experience doing this kind of slightly different use-case than regular in app purchases?

Answer 1

Don't worry about explicitly unlocking the app. By having the app's functionality depend upon the hardware, the app is implicitly unlocked by using the hardware.

For example, have the app check for the hardware at the appropriate times. If the hardware is there the hardware will do the appropriate task. If the hardware is missing the app will notify the user to attach the hardware and include a way to find further information on acquiring the hardware.

Maybe the app will produce reports without the hardware attached. The unlocking aspect will be accomplished by not having any data to report until after the hardware has been used to collect that data.

Alternatively, put the app in the App Store as a paid app. You can give it away with your hardware by making it a $9.99 app and include a $10 App Store gift certificate. This will cost you about $4 per app after Apple's cut and the added manufacturing costs. On the one hand, you risk customers not buying your app, but spending the certificate on Angry Birds. On the other, maybe you'll get some direct sales of the app.

In your situation, I would probably just give away the app, and include advertising for the hardware. I'd include on most screens (maybe every screen) an unobtrusive "brought to you by . . . " line. In an about screen I'd include a link to the website to order the hardware. If the app truly needs the hardware, nobody but the hardware buyers will download it. If the app truly enhances the hardware, every hardware buyer will want it, and appreciate the value added.

I don't think an unlocking code after buying your hardware will be acceptable to Apple. This is clearly a sales transaction that doesn't give Apple their cut, so they won't let it on the App Store.

Answer 2

I think the way most apps that do this kind of thing work is that they have you register your hardware online (thus creating an account in the process), and then have the app prompt you for your registration information when you launch it.

If you don't want to do that (e.g., if you don't want to have to manage your users online), then maybe you could have them enter in the hardware's serial number when they first access the feature?

You might want to look at the Withings internet scale + iPhone app to see one possible technique.