If you are aiming on iOS and Android with Windows Phone 7/8 as a plus you should use C# as the language and Xamarin Studio as the IDE/Framework. You may also choose to use Visual Studio on Windows as an option.

Take a look on their website: http://www.xamarin.com

Even Microsoft is using Xamarin to build iOS applications and they have over 400k developers using it. Your application will be native (compiled to the platform you choose) and you are able to use all the native libraries, widgets and UI parts.

You will need a cross-platform architecture to be able to reuse code among platforms and using Xamarin you may be able to reuse more than 50-60% of your C# code among platforms.

This solution may render the same experience on the devices as on the website, but it enables your applications to deliver much more performance and features than any HTML5 solution. Facebook went from HTML5 to native applications due to performance and user experience limitations (gestures and other platform features are not present using HTML5).