ZXing - Barcode Scanner for Android
Stocard - All loyalty cards on your smartphone!
QuickMark - QuickMark makes everything possible.
Pass2U Wallet - Put cards into Apple Wallet
QR Droid - QR Droid Zapper
PayPal - PayPal is the faster, safer way to pay online without sharing financial details, send and receive money or accept credit and debit cards as a seller