What is a review checker?

Maybe this will help (from a Gemini response):

Fakespot: This was a very popular and often recommended review checker that analyzed product reviews to determine their authenticity. However, Fakespot is shutting down on July 1, 2025. This is a significant change, as it was integrated into platforms like Firefox's Review Checker.

Review Meta: Similar to Fakespot, Review Meta allows you to paste a URL of an Amazon product and receive an analysis that filters out potentially untrustworthy or fake reviews. It categorizes reviews as reliable, suspicious, or fake, and provides an adjusted rating.

Firefox Review Checker (powered by Fakespot): As mentioned, this feature in Firefox that assessed review quality on Amazon, Best Buy, and Walmart will also be shutting down with Fakespot.