I wanted to use my Tablet as a touchscreen monitor for my computer.
To do so, I installed Vino:
sudo apt-get install vino
Disabled the encryption (I'm on a secure intranet):
gsettings set org.gnome.Vino require-encryption false
And started the server:
/usr/lib/vino/vino-server &
On Android, I downloaded bVNC
And connected to port 5900.
Magic ensued.
A 1:1 size ratio between the tablet and the monitor would be helpful: it's difficult to get the mouse pointing in the right direction.