Convert existing iOS paid app to freemium model with in-app purchase

Question

I currently have a paid app in the store. Apple have not allowed a 'lite' version to be submitted as well, so I have no choice but to update the current paid version to a freemium (with in app purchase) model. I have the problem of not loosing functionality for v1 users that have purchased the app the first time round.

Is there any way to determine if an application have been updated from a previously installed version so I can unlock the paid parts of the app?

Two similar questions (from a few months ago):

Transition an existing paid for app to free version with In App Purchase

iPhone + upgrade existing paid application on app store to free application with In App purchase + what about the customers who have already purchased the paid application

Answer 1

There is now an Apple-approved way to do this on both iOS and macOS. The originally downloaded version of the app can be obtained from the receipt using the info key Original Purchased Version. You can then decide whether to unlock features if that version predates the switch to IAP.

For instance, once you have retrieved the receipt info:

NSArray *versionsSoldWithoutIAP = @[@"1.0", @"1.1", @"1.2", @"1.3"];
NSString *originalPurchasedVersion = [receiptInfoDict objectForKey:@"Original Purchased Version"];
for (NSString *version in versionsSoldWithoutIAP) {
    if ([version isEqualToString:originalPurchasedVersion]) {
        // user paid for the currently installed version
    }
}

For more info see the WWDC 13 video Using Receipts to Protect Your Digital Sales. At 5:40 the presenter comments: "I think the most exciting thing that's in the receipt this year, especially for you guys if you have a paid app in the store is that we've included information in the receipt that's going to let you do a transition from being a paid app to being a free app with in-app purchases without leaving behind all the customers that have already paid for your app."

Answer 2

With iOS7, iOS app can verify app store receipt, which contains app download date. By using this donwload date, you could determine if a customer is previously purchased or not

Answer 3

First, I just want to say I personally think the freemium model is great. It has worked out very well for many developers. People love to download free apps, and will do it on a whim, but pay much more attention to an app before spending $0.99 (Which is due to the effect of free - for more info on that, check out Dan Ariely's book Predictably Irrational)

For more info on freemium, google it - There have been tons of articles written about the success of it.

---

Ok, back to the actual question:

Theres a couple ways you can handle a situtation like this, although the unfortunate matter here is none of them are fool proof.

• The best solution would probably be for your users to have accounts. Without knowing the specifics of your app, I can't say whether or not user accounts are appropiate for your app. User accounts stored on your server have many additional benefits, including user management, and tracking what purchases a user has made. This will allow users who delete the app, and then re-install it, or get a new device, to maintain their purchased content. Furher, whenever you use in-app purchase, you should validate the purchase on your own server (or with Apple), which a server based user manegment system can all do. If your totally in over your head with creating your own user management server, check out Parse. Its dead simple to create an amazing backend server (for basically free)
• iCloud Key/Value type of system. I'm not very familiar with how this would work - so I'll move on.

• Another, not nearly as fool proof solution (but much quicker/easier to implement) is to use NSUserDefaults. You can store an object when the user makes a purchase, or with the date a user installs your app. Then if you issue an update converting your app to freemium. Then in the new update, check which purchases the user has made or the date they installed it, and react accordingly. For info on how to do that with NSUserDefaults, check out my answer to another question on implementing that: NSUserDefaults and app versions. But this solution does present the following pitfalls:

• If the user deletes your app, the NSUserDefaults are lost forever

• If the user didn't install the update setting up the NSUserDefault system, but then installed the update with the new freemium model, the app would treat them as if they hadn't purchased the content.

In summery, this is a difficult question, with not a lot of easy/perfect options.

Anyway,

Hope that helped!

Answer 4

I'm dealing with the same thing and came up with the following idea: Create the freemium version under a new name and app ID. Keep the existing paid app in the app store, but raise the price to something absurd and clearly state in the description that the app is there to maintain support for existing users and that new users should try the freemium version instead.

Existing paid users won't lose support for their existing app and can delete and install any time it without re-purchasing.

You won't have to keep updating the old paid app, either. Just keep it in the app store.

The downside is that existing paid users will not be able to migrate smoothly to the freemium version to get any extra features you add in the future without re-paying for what they already have.

Still trying to decide if this will work for me but it could be a good option for others. Comments appreciated.

Answer 5

I've been thinking about this problem for some time now. I have a substantial amount of customers that paid for my (in App Store terms) high-price niche-App and I'd hate having to tell them to re-purchase as I plan to migrate to an In-App Purchase model.

The idea I came up with (and I'll ask Apple support whether it's legal) is to phase out the current paid App but ship a last update for it that allows "unlocking" the In-App purchases of the new App based on the In-App model. I was thinking about a challenge response scheme:

• User has installed paid App on his device
• User installs new In-App App and opens it. The new App detects the paid version and offers to unlock the In-App purchases (on this device only of course and as long as the App isn't deleted)
• The new App generates a nonce, signs it and calls the old App with it via an URL Scheme
• The old App decrypts the nonce, adds +1 one to it and signs it again. Calls back to the new App via URL scheme
• The new App validates the nonce and unlocks the features

The scheme can be easily implemented using a pre-shared key. It's of course a weakness on jail-broken devices, but then every App storing In-App receipts has those problems.

Answer 6

You can check the 'original_application_version' of the receipt. All iOS downloaded from the appStore have a receipt even if it is a free app.

TPInAppReceipt is a simple swift library that can help you with this.

import TPInAppReceipt

do {
  /// Initialize receipt
  let receipt = try InAppReceipt.localReceipt() 

  let originalAppVersion = receipt.originalAppVersion
  let buildSoldWithoutIAP = 22

  let originalAppVersionInt = Int(originalAppVersion) ?? 23
  if originalAppVersionInt <= buildSoldWithoutIAP {
                
      // unlock all features
      UserDefaults.standard.set(true, forKey: "isPaid")
  }

} catch {
  print(error)
}

Note: The receipt.originalAppVersion returned is the build number as at the time the user first purchased the app from the appSore. Also, the receipt won't be available in the sandbox environment until you purchase or restore an inAppPurchase first.