Hi,
Thank you for your interest in BubbleUPnP.
You can install the purchased 'BubbleUPnP License' app on all your Android devices having Google Play
installed and using the same Google account that you used to purchase it.
To install the 'BubbleUPnP License' app, in BubbleUPnP go into 'More > Buy/Restore License'
and tap the 'Buy/Restore License on Google Play' button. This will
bring you to the Play Store page for the 'BubbleUPnP License' app
and you can tap the 'Install' button.
If instead you see a 'Buy' button, you can try to install it from the web Play Store (logged with the proper Google account):
https://play.google.com/store/apps/details?id=com.bubblesoft.android.bubbleupnp.unlocker
If the green button is labelled 'Installed', click on it to reveal additional devices to install it to.