Default [Q] Help on porting tools from VS .Net 2010 to Android apk

We have a web application developed on VS .Net 2010, framework 4. using HTML5, JavaScript and JSON (formatted output). This application has not been designed for the mobile.

The requirement is to convert this web app into the Android platform without much effort.

Is there any tool that we can use to achieve this in less time.

Note:
We tried converting a sample app in HTML5 JavaScript JSON using Phonegap. It works for the simple application (one screen), but I would love to hear about alternate tools and the pros and cons of each product.

Thanks in advance.