display xubuntu desktop on android tablet

I want to use my android tablet as a secondary display for my Xubuntu laptop, not to mirror the laptop but as an additional desktop -- I do not need to drag windows from one to the other, and it is okay to run the android session as a separate login.

Ideally I would like to use the keyboard/mouse of the desktop for the android session, but I can live without. If possible I would like the connection be made via usb instead of wifi (to help save battery).

On the askubuntu archive I found a post with almost the same title & question

How do you use an android tablet as a second display?

The answer is to (1) install vnc4server on the laptop, (2) get a vnc client on android, (3) connect the two, and (4) share keyboard and mouse using synergy. I have done (1) and (2), and following

https://superuser.com/questions/182261/how-to-change-virtual-screen-resolution-on-ubuntu-connecting-via-vnc-without-re/187274#187274

I started the vnc server using

vncserver :12 -name "My-Server" -geometry 1024x600

Unforunately I'm not sure how to proceed with (3) and (4). I tried to initiate the vnc session on the android by firing up "androidvnc viewer", but I don't know what to enter for port (default seems to be 5900?) and address. Also, what should I use for "color format" -- 24bit or 16bit?

Speaking of address: As I said if possible I would like to connect the tablet and the laptop via usb. What should I use for address? Alternatively, what address should I use if I need to connect the two via wifi? In case that matters, I could be working in setups where neither devices have internet connection to the outside world (!).

Last but not least, upon reading old posts about vnc I found discussions about tunnelling vnc over ssh

How do I start the VNC server?

The post above uses x11vnc; is there a similar option for vnc4server, and how would I proceed on the android side? I also found

http://www.cyberciti.biz/tips/tunneling-vnc-connections-over-ssh-howto.html

But I'm not sure how to incorporate that into steps (1)-(4).

There is also the question of using synergy, but that's probably for another post :-)

THANK YOU for you help and patience.

You need a VNC viewer for Android. There's a bunch of free ones in the Android store.

You shouldn't need to setup SSH tunneling.