Ask HN: Reviews app that plugs in like disqus

Is there a company that creates a reviews app that I can plug into my site, something like Disqus. I believe a heard about a company like this that got funded while back. I tried google and angels list and came up empty. So does this exist? If not is there a company that I refer my customers to that has a review system similar to amazon? If not is there a company that I refer my customers to that has a review system similar to amazon? Thanks