The future of money is in your pocket — the one you keep your phone in, not your wallet. A growing portion of the world’s population is making phone-assisted transactions. They’re using a variety of technologies, from the text-message system popular in Kenya to the seamless credit card-and-app arrangements that move money for every Lyft and Uber ride. It’s a revolution that’s lagged in the U.S., despite offerings from Apple Inc. and a range of big retailers. In addition to providing convenience and sometimes lower fees than credit cards, these mobile-payment systems are connecting millions of previously unbanked people: In China, some beggars hold out bar codes instead of tin cups. In places such as Sweden where the apps are especially popular, cash is starting to disappear. And beyond the cash register, it’s clear that a good chunk of the traditional consumer-banking business stands to be upended.