Gold and purchased upgrades are specific to each platform, and cannot be transferred between platforms. (For example, we aren't able to transfer mobile purchases to Steam or vice versa.)

If you are playing on mobile, you can sync your progress to Google Play (Android) or Game Center (iOS). This should transfer all of your progress, including your purchases.

If you're moving between iOS and Android, contact our in-game support team (tap menu > "Help & Social" > "Contact Support") and we'll be happy to assist you with your transfer!