i have a solution for you douglas
create an app with some panels and some buttons, something simple that should pass the apple review.
in the app also place the webview, after apple approve your very simple app (with some buttons that do simple stuff) you can change to only webview.
what i mean is on app start app download a file from your server if file.string is 0 behave like a simple app for apple if 1 show only webview on app start
you can store that value that also if phone is offline it will start only with the webview.
i believe after approve your app apple will not check it again only until the next version and then you can do the same.
good luck.