Paribus - Find out for free if online stores owe you a refund!
KOHO - KOHO is a place where you can access your money in real-time and get instant cashback.
Lolli - Earn bitcoin when you shop online
Upromise - Upromise is the cashback coupon and rebate site.
ShadowBid - iOS App - A simple iOS app to automate saving money on Amazon
TopCashback - TopCashback names itself the UK’s most generous cashback site. They offer cashback on over 5,000 retailers with a variety of payment methods including gift cards, PayPal and bank transfer.