As Film Story (free version) and Film Story Pro (paid version) are two different apps, purchases cannot be transferred to the other. Your understanding is greatly appreciated.
For those who bought Pro as an add-on to your Film Story,
Once you purchase add-ons on the app, there will be no additional charge. It will be a one-time payment. Once you delete the app, it will go back to the free version, however, you have an option to chose “purchase” or “restore” on the app and it will be restored.
(Even if you chose “purchase,” as long as you use the same AppleID, there will be no charge.)
For those who purchased Film Story Pro,
There is no charge within the app. You can download the app again for free from AppStore.