Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
Freebird - Freebird is a cashback and shopping rewards platform that allows anyone to participate at no cost.
Fetchee - Fetchee is a free price tracking wish list app that works with all online stores worldwide.
Earny.co - Win prizes on Amazon purchases
Keepa - Price history charts and the option to be alerted on price drops for all Amazon sites.
Lolli - Earn bitcoin when you shop online