Lightning to Audio 3.5MM Adapter Headphone Jack (Apple iPhone etc.) - £1.99 / USB C 3.5mm Adapter £2 Free Collection @ Argos

The official Apple one is an incredibly cheap and incredibly good DAC. As it's TRRS (combined headphone and mic port) I use the Apple USB C version with my laptop as a tiny travel audio interface for my broadcast headset and it's superb.

This one is unlikely to have anything as good on board and while third party ones are generally fine for light music listening, they don't always work for calls or for using as mic inputs. Some work fine but it's hit and miss so if you want to use a headset/mic (for calls or recording) or drive decent headphones, I'd pay (and this is not normally I'd usually say about Apple gear) the few quid extra and get the Apple branded one. (edited)

Compatible with any iPhone with a Lightning port (so yes).

It's in the description. Not much stock though. I'd recommend the Apple USB C headphone adapter, which is only a few pounds more and is excellent quality.

This plugs into the lightning port on a phone at one end and accepts a 3.5mm plug at the other. No Bluetooth involved.

Worth noting that the next iPhones that we see in Europe could well have USB-C instead of lightning. Which may go some way to explaining this price reduction.

tomsguide.com/new…eak

You can either charge wirelessly or use a Belkin RockStar Audio + Charge which gives you a headphone socket and Lightning charge port (or there's also a version with two Lightning ports - one for audio and one for charging). (edited)