Build once, deploy to any smartphone

You may use a hybrid solution. This is a native Objective-C solution with the web-based solution (HTML, Javascript, CSS) embedded. You will need an Intel-based Mac OS and the iPhone SDK to create this kind of project.

The best framework to use is PhoneGap. You will get the the basic xCode, android etc templates and inside the build folder, there is a HTML folder where you insert your web files into (index.html, etc.)

You can also point your UIWebView control to an online URL and create just an application with icon and AppStore distribution that only work as a Mobile Safari without the toolbars. All your files will be on your web server.

If you only want to have the users an icon in the Home Screen, you don’t need the AppStore. You can just use the meta tags available in Mobile Safari.