Most of the "supported" merchants no longer work, Walmart is the only one that consistently drops prices and honors Paribus requests. Used this primarily for Amazon and Best Buy purchases, neither of which have worked for me in quite a while. The new update may bring promise with the possibly of Discover card price protection in the future, but for now it is generous to give it 2 stars.
Eborch about Paribus: Money Back Shopping, v2.2.3