Shopper

What it does

Skips the knockoffs, compares prices and specs across official stores and marketplaces, and takes the cart as far as checkout. It runs when you ask it to, rather than on a timer. Filtering the counterfeits before comparing prices is the right order: the cheapest listing for a thing is very often not the thing.

Before you install

Open the share link and read the instructions it carries before you add it. @FranciscoKemeny shared this one publicly, and adding it copies the setup into your own account rather than giving you access to theirs.