Using Android as touchscreen monitor? Is there an app?

I have a Nexus 7 2012, and think the screen is great. It's a huge part of the reason I went with a tablet, rather than a computer. Unfortunately, there are some limitations that I really don't care for, and device capability is one of them.

I know that using a Febon HDMI UVC interface, it can be used as a monitor easily. I also know that there are apps that will allow you to use the tablet as a touchpad.

So the real question is, does an app exist that allows the touchscreen to be used to control a Windows machine, while displaying what the monitor output does? If not, how hard would something like this be to do?

Thanks!
Eric