This is why CurrentC will fail:
"Users have to open their phone, open CurrentC, open the scanner, scan the code from the cashier, and wait for the transaction to be confirmed."
It's far easier to just swipe a credit card or to use an NFC based payment form.
I find this whole attempt to wrest control of payment processing from the credit card companies annoying and kind of amusing. Here, please use our awkward payment system so we can cheat credit card companies out of their processing fees. For you? Oh, maybe we'll give you some loyalty points that are only usable here at <insert retailer name>.
Are they kidding? I'll take real cash back from the credit card companies instead any day. And those places that don't accept credit cards or try to charge me a higher price for using one don't get my patronage.
I also find it funny that the two big retailers on board are from an ancient and dying market segment, drug stores.