If you have previously purchased one or more of the stages but your device has not unlocked it here is how to fix this:
Firstly, please make sure to use the same Apple/Google account to sign in to your device. Any purchases you make (for any app) are tied to your account and unfortunately cannot be transferred. If you have changed your Apple/Google account and have previously purchased stage(s) then please email us at firstname.lastname@example.org and we will provide help.
Whilst connected to Wifi tap the "Restore purchases" menu option
Uninstall the app and then download and open the app whilst connected to Wifi.