It is never 100%, things age out companies change up to avoid the savings, and so on. It does work though and I have save well over $1,000. It is worth the free install for sure.

Best credit card I've ever had.

Totally forgot I had the extension - was in the middle of buying something and was about to confirm the purchase when all of a sudden it applied a coupon code for me. Saved me $30 bucks!

This App is great. Once it determines what you're shopping for, It automatically hunts down the lowest price available on the internet for the item with almost no help from you.