We speak your language gadget

I am considering using the we speak your language gadget and would like to know if anyone has used it on their site. Is it a good tool which may help increase visitors to my site. How does it work. My site is visited by countries all over the world and I am not sure what difference adding this gadget would make. I would also like to know on what page the gadget would be added or if it would be available on all pages of my site (www.myqualitywriting.com).