I need a simple way to customize the screen of the BarcodeScanner. How do I do this?
I assume you are referring to: https://github.com/phonegap/phonegap-plugin-barcodescanner
If so you just need to fork the project and customise the scanner overlays.
For example (iOS): https://github.com/phonegap/phonegap-plugin-barcodescanner/blob/master/src/ios/scannerOverlay.xib
Do you have any tutorials that teach you how to do this?