This works great with Firefox Quantum 59. I like that the icon only appears when I'm on Amazon, rather than cluttering up the toolbar all the time. My only quibble is that when I first installed it, it didn't work on smile.amazon.com, only on the regular Amazon site, but this seems to have been fixed now.

Works great with Quantum 59+. Detailed pricing history really kills those impulse buying habits Amazon encourages and offers price notifications set to your limits. Great addon so far, considering how much I use Amazon. Love it.

Love this app! It's like being able to put a limit-order on an amazon item. Getting a message when the price drops below a threshold is awesome. I sometimes buy an item 6+ months after I originally see and mark it on camelizer.

For those complaining about incompatibility, I have been through every update of FF for the last 1.5 years, and am currently on FF 58.0.2, and have successfully used this extension -- alongside ublock origin, print edit, video download helper, user agent switcher, and with and without flash or java.

Excellent. The way prices bounce up and down on Amazon, this add-on provides a great way to highlight when the price drops to what you want to pay, as well as being able to see a history of the pricing.

I like it

Support has released v 2.9.5 that successfully addresses the blank page encountered by some in v. 2.9.4.

It's a wonderful app, but the newest update broke it. The icon in the taskbar/menu is missing entirely. The app is installed, but there is no way to actually use it right now.
--- EDIT ---
it appears that the icon is in the address bar. I didn't even notice it moved. 5stars