Although the Testflight version and the final version are the same build, they are treated as separate apps by Apple. The Testflight version will stop working in about 2 months so you need to download it from the App Store at some point. The App Store version will overwrite your Testflight version so that your data will remain but the simulated In App Purchase from the Testflight version will be invalidated. You will need to do a real purchase with the App Store version.
So to move to the final version you need to:
- Open App Store and download Stage Traxx 3
- Open ST3, go to settings, select In App Purchases and select the Unlock entry.
For future releases I will be using a separate beta app so that it will not interfere with the stable version.