Will Apple App Store approve web apps that directly using online URL and resources?
Yes.
When I submitted my app to Apple App Store, I was worrying about a rule that forbidding downloading code in any way or form. And as a web app that downloads its main code only after installation, it does seem to violate this rule. But luckily, it’s finally approved.
Apple App Store http://itunes.apple.com/app/id843170841
See also the Windows Phone version http://www.windowsphone.com/s?appid=a3e70b25-b048-4bef-996f-cc2b30a6eda2
And congrats to myself that WordsBaking is scheduled to be FEATURED in Windows Phone Store (China) tomorrow. 😉