I am developing IAP functionality of non consumable (removing Ads).
I've created an helper for all the operation and everything works fine.

When a user buy/restore the purchase i set this:

```
let save = UserDefaults.standard
save.set(true, forKey: "Purchase")
save.synchronize()

```

This works fine as long as the user never delete the app.

I was wondering...
Is there a way to know if the user (after deleting and reinstalling the app) already had made a purchase? so to change the title of the button from "purchase" to "restore"?