How to prevent abuse of app free trial period (non-subscription)?

Question

I'd like to provide a free trial period for my app and then the option to buy it with in-app purchase.

The problem is Google only provides free trial support for subscriptions (recurring payment), but not for one-time purchases, so I have to roll my own check for the end of free trial.

The problem is the user can simply reinstall the app when the free trial period ends to start it again, because the app does not require an account to use. Requiring an account just to check the free trial period hurts the user experience, because many users may refuse to use an app if it demands logging in to an account for no reason.

Is there a way to reliably check the app free trial period without making the user to log in to the app?

Answer 1

I'm looking to do the same thing - in my case allow a trial of a subscription without having to have payment details on Google Play.

My understanding is that allowBackup=true in the manifest results in the app's SharedPreferences being stored in the user's Google account in the cloud, and restored whenever the user installs that app on a device.

I haven't tried it yet, but it seems suitable.