OpenDisplay- gives your Mac a real extended display using an Apple device you already own – Newsshooter
[REF]:
https://www.newsshooter.com/2026/08/26/opendisplay-gives-your-mac-a-real-extended-display-using-an-apple-device-you-already-own/
If you have an old iPhone or iPad, you can turn it into a working second display for free using a new piece of software called OpenDisplay.