Both iOS and Android support sharing the app between multiple devices but have to be aware of couple things.
- Devices should use the same Apple ID.
- Piano Companion PRO could be downloaded without payment.
- Activate In-App purchases.
- Make sure that devices use the same Google Play account and you have the network connection.
- Piano Companion PRO could be downloaded without additional payment.
- Activate In-App purchases in Piano Companion FREE by taping Shop icon and Android should activate In-App purchases linked with your account: