Competera - Competera is a price tracking tool for performance-oriented eCommerce retail and brands of all sizes worldwide.

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

ResponsiBid - ResponsiBid is a software that helps bidding and estimating for cleaning companies.

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

Revionics - Revionics offers lifecycle price, promotion and markdown optimization solutions for the retail industry.

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