In Apple's Q4 earnings call, CEO Tim Cook announced that you could buy an iPhone on an Apple Card later this year, pay it for 24 months without interest, get 3 percent cash back on the purchase, and pay in the Wallet manage app with one blow.
Apple already offers a number of ways to finance the iPhone's costs, such as the iPhone Upgrade program, and it seems that only the "manage payments in the Wallet app" is really new. Apple already offers Apple Card holders 3 percent money back when they make purchases in stores, and lets your phones pay in 24 installments while you get the money back if you make those payments – on time – with an Apple Card.
With a "later this year" timeline for the new repayment plan, it seems possible that this benefit will be introduced sometime before the holiday season.
Apple Card users can also get 3 percent cash back at T-Mobile, Walgreens and Uber.