There's no need to buy a separate device.

In a pinch for extra screen space on your PC but don't have a second display? Use this simple USB trick to turn your Android tablet into a portable monitor.

I literally have no idea how using your S9 Ultra as a 2nd monitor works, you mention both wired and wirelessly which doesn't help clarify at all. Could I ask you to explain that to us? But at a lower ...

spacedesk is a free program that turns an Android tablet into a portable display for your Windows PC that you can easily carry with you anywhere. You can use it when you need extra screen space or ...