Private "Google Wallet" application.
Budget: $250 – $750 USD
Private "Google Wallet" application should be free from from 2FA verifications. And for privacy reasons the ability to tap-n-pay without Google find out where and when the person made its shopping. The ability to add at least 5 cards active all the time.
Related categories:
Mobile App Development
Android
Cryptography
Near Field Communication (NFC)
Payment Processing