Hi,
I like the widget overall I still don't know if it increased my conversions but will report back when I have the data, here's my suggestions:

It would be nice to let us create our own buttons, that way you wouldn't need to translate to all the languages, and we could be able to make custom buttons based on a service page.
Example: a button with the text: Give us a review about our "something" service/product.

Something that would also be nice is to let us be able to choose manually which reviews to display.
Example: I only want to show reviews about x service on x service page... That would work for the reviews where clients include the service name.

There's room for improvement, but it's a great start for such a simple widget!

I will update the review when other most used languages will be added.