what apple devices are eligable

Skydiver there is this for iOS devices.

Apple Trade In - Apple

You get very little to no trade-in money for any 7, 8 or 9-year old iPads.

If you have a 1st gen iPad Air or later or an iPad Mini 2 or 3 or later, Apple's trade-in partner may give you some cash toward a trade in toward a new or refurbished iPad.

Best thing and easiest thing to do is just go to your nearest, “local” Apple Store, bring your current iPad and let them determine if their is any trade-in cash value.

You will bypass Apple's trade-in partner and having to deal with having to ship this iPad and packaging up tbat iPad well and insure it to protect it from getting damage in shipping or by the Apple's trade-in partner.

Look at this link here anyways to see what your old device is worth, if anything.

Apple Trade In - Apple

See what an actual visit to a “local” Apple Store will do for you!

Best of Luck to You!

None.

There is a phone upgrade program, but you basically pay a monthly fee to ‘lease’ or ‘rent’ the device

https://www.apple.com/shop/iphone/iphone-upgrade-program

Beyond that the only way you can trade a device in for a new one is if your device is under factory warranty and it’s determined that your device is suffering from a manufacturer’s defect. (And even then the device may be refurbished, not new)