Keepa is an excellent tracker for Amazon pricing. I haven't used other Amazon price trackers besides Honey, and I think Keepa blows honey out of the water.
It seamlessly integrates with the Amazon product page without being annoying, and allows you to setup alerts on product prices and lightning deals regardless of seller. The in-page graph makes it exceptionally easy to see if now is a good time to buy, and also makes it easier to see if its worth reviewing used options.
Additionally, Keepa requires a narrow scope of permissions which I highly value, only pulling information on amazon owned domains. This is far better than apps like Honey that request all of your browsing data.
I love this app and highly recommend it to anyone who uses Amazon.
