What about the customers who have already purchased a paid application when upgrading it on app store to free application with In App purchase? [duplicate]

Question

I have implemented In App purchase in my existing application.

This application is currently available on app store as paid application, I want to update this paid application to free application with this In App purchase feature, where users can download it freely and have to pay for few features to unlock them.

But the problem is that, if I update the existing paid application as free application (with few features locked and user has to buy it to unlock it), what about the users who have already purchased this application.

Because when they will update to new free application, few features will be locked and they have to pay again to unlock them (why should they pay, if they have already purchased whole application previously).

Answer 1

How about releasing a new paid version which writes some data to the application's data store recording the fact that is the paid edition. Then release a new version of the same app that is free but obviously does not record that. However, the free version looks for the data written by the paid version and unlocks the premium features if that record is found.

The only downside is that you'll be depending all paid users upgrading to the new paid version before you release the free one.