Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.

Optmyzr - Optmyzr AdWords Tools. Optimization Solutions, Quality Score Tracker, Landing Page Checker, and more. Free Trial Available.

Fetchee - Fetchee is a free price tracking wish list app that works with all online stores worldwide.

LiveIntent - LiveIntent is a web platform that offers effective e-mail advertising services for marketers and publishers.

Keepa - Price history charts and the option to be alerted on price drops for all Amazon sites.

Affise - Affise offers performance marketing solution to manage and analyze affiliates, advertisers, creatives, conversions, offers, and payments.