This extension provides seven characters that are used to write most of the world's languages.

When you press the button on the extension, you will see a drop-down that will allow you to choose from either the Devanagari or the Roman Script. When you make the selection, the entire page will be transliterated.

The English page was created using this extension. Here, you will see that when you press the button, the entire page will be translated.

The seven writing systems supported are:

Bengali, Gujarati, Punjabi (Gurmukhi), Kannada, Malayalam, Telugu, Tamil.

The Devanagari page has been created with this extension. Here, you can see that the text will be transliterated. 

This extension is not able to translate words. It merely transliterates. You still need to understand the language to understand the page.

There is no option of transliterating the Devanagari into Roman Script at this time.