Its an app run by quidco as is clicksnap.
They list various offers, some good, some rubbish. But you upload a photo of your receipt and they pay you for the offers you qualify for.
So, they might offer 50p off a £5 shop plus £1 off a certain brand of crisps but if you buy the crisps in a supermarket that sells the crisps for a £1 then it's free crisps.