Do I have to buy a new license for every iOS device I own?
Don't worry – for each iOS device you own you don't need to buy a new license of Scanbot Pro.
To download the app again, just to go the App Store, search for Scanbot and download the app.
Scanbot will automatically search for receipts on your account and restore your Scanbot Pro Features to your new device.
Please note, that it is not possible to use your iOS purchase for Android devices or vice versa. The conditions in the iTunes App Store and Google Play Store don't offer such cross app store pricing.