NoScript(または同種のアドオン)を無効化すると使えるようになります。

NoScript でAmazon上のすべてのスクリプトを許可してもダメなので注意。
NoScript の対応に期待。

I've used this many times to track deals on amazon - easy to use interface, awesome app. Highly recommended.

This tool is amazing and really helps gain visibility on the price fluctuations. It has also helped me avoid scammy lightning deals.

This is a superb add on. Working in additon with Keepa.com it can really save you money - it has saved me a good bit over the last year or so. Thanks to the developers

This plug-in really helps me a lot.
I also like to buy on AliExpress.com all worth a penny and much cheaper than you will find on the internet.
I suggest a good plugin-browser to view the history of changes in prices on AliExpress.com - is very helpful to determine the cheapest price from the seller, and to find this product in other sellers on the following link: https://goo.gl/u4lMcU
If you want return 18% off any purchase on AliExpress.com and other stores register on the link: https://goo.gl/7jb6Lr

This extension has been very useful to me and worked very well, but now I have (after inactivating all my extensions one by one) realised that Keepa has started causing some pages not to load. Any pages, not just on Amazon.

Reply to creator: Thanks for the quick reply. Glad to hear there's a solution coming.

This plug-in really helps me a lot,i've found lots of this sort of price tracer plug-in before,all of them charges or need Proxy which really troubles me..
all the way,author of the plug-in thx：D