Freetobook have created a widget specifically for highlighting your great reviews on your website!
Log in to freetobook and navigate to DIRECT BOOKINGS tab and then BOOKING BUTTONS. You will see the option for RESPONSIVE REVIEWS and will find the javascript code which should be pasted to your website in the normal way.
Please note that if you are using iframes on your website AND intend to use the review widget with calendar and “check availability” button you should use the dedicated code for this so that the booking process works smoothly. More detail can be found here.