Smartphone application developers, along with banks and merchants, have been in search of the mobile payment method that can "go viral."
Many apps are already available with payment functions, including various "wallet" apps - Google Wallet, Square Wallet, Lemon Wallet. Others are waiting in the wings, including Flint and Clinkle, the latter a well-financed effort with the backing of Virgin Group founder Richard Branson. Apps for some coffee shops, including Starbucks, have payment features for your caffeine fix.
Among all these, Minh Tran is one independent developer who hopes he has the go-viral formula that will work.
Tran, 39, who several years ago launched an app, now called Fix311, for reporting potholes in a number of big cities, has a newer offering, CardSwapp Lite, for Android and Apple smartphones, that lets users make and take PayPal payments by scanning those two-dimensional bar codes called QR codes.