[kjaftaedi]

When I was doing this, I would just use a tablet.

Android, iPad, Windows, they all have monitor extending software and have for at least a decade now.

Saves you the need to by a screen if you've already got a tablet lying around somewhere.

[crtasm]

Can you do this over a wired connection on Android?

[rchaud]

Not the OP, but I have tried Duet Display on Android and it only works via Wifi. Samsung Galaxy Tab S7 (the premium price series) can be used as an external monitor, but only for Windows machines.

[crtasm]

Thanks, I wonder how vulnerable to sniffing the wifi solutions are.