How do I use Snapper to pay for things in retailers?
At a Snapper retailer just ask to pay by Snapper. When prompted by the retailer, touch your Snapper to the Snapper reader on the counter.
Snapper is really quick, so if you want to check how much you're paying and what your balance is, make sure you keep an eye on the information displayed on the Snapper reader before, during and after you use your Snapper.