If you're looking to buy a new Apple device, using its own trade-in service is a good, hassle-free option, especially if you want to finance some of that purchase with your existing phone, tablet, or computer.
The company will take other manufacturers' products but gives the best prices on its own. This isn't the best service to use if you want a quick turnaround on payment, as it can take two or three weeks to process unless you do the trade-in at an actual Apple Store retail location.
However, the company will send you packaging with prepaid shipping customized to the device you are sending back, making the entire process very easy to deal with. To use this option, go directly to Apple's trade-in site or choose "I have a device to trade in" when purchasing a new device from the Apple Store.
Payment: Apple Store gift card or trade-in value during the purchase of Apple products
Turnaround: Instant at an Apple retail store, two to three weeks if done online