As I understand it, you don't need to worry about backwards compatibility. You submit these pseudo-XML views along with your app when you publish it but what th

As I understand it, you don't need to worry about backwards compatibility. You submit these pseudo-XML views along with your app when you publish it but what they do from there on out is up to them - they could "recompile" them to newer versions, they could compile them to some binary representation, whatever. But anyway, it's not your problem. Your responsibility is getting the app to the app store, their problem is getting the app from the app store to the devices, in whatever format they see fit. Despite the technological similarities, this isn't publishing to the web where you have to handle everything by yourself.