I haven't found any stores that can actually scan the barcode off my phone (using keyring), but I can open it up and they can usually type it in manually. Its also really helpful for when I ned to log on to a store website. I used to have to go find my wallet. My phone is always next to me tho.
(from Beka's DX)
I frequently use Keyring at the following with successful scans.
CVS (100%)
Walgreens (100%)
Hallmark (about 50% of stores)
Martin's Food Stores (100%)
Dick's Sporting Goods (100%)
Food Lion (100%)
This app is fantastic!
Bob