More details have come out about Apple's rumored plan to allow iPhone owners to trade in their old devices for credit toward purchasing a new one. According to TechCrunch, such a trade-in program is already live in several Apple Stores as part of a test run, and it currently allows owners to get around a $120 to $200 gift card in exchange for a 16GB iPhone 4 or 4S, depending on its wear and color. It's a small sum to receive for a working phone, but it would be enough to cover a new device when sold on a two-year contract. 9to5Mac reports that a proper launch will occur in September.

Though many third parties have offered iPhone trade-ins, this would mark the first time that Apple has run an official program. It's believed that Apple is planning on using the program to acquire iPhones that it can refurbish and then resell abroad to emerging markets. And according to 9to5Mac, the program may also be part of a broader plan to drive traffic to Apple Stores. Only 20 percent of iPhone sales reportedly happen in-stores, and the trade-in program is said to be a means of addressing that. The goal apparently isn't just to bring iPhone sales in-store, but also to make sure that customers see what else the Apple Store has to offer — and sell.