iPad (Air) as 2nd screen using Lightning cable? I travel a lot and use a MacBook Air as my primary machine with an iPad Air for secondary tasks. Occasionally I find it would be useful to have a second screen, but because I don't have a fixed work location carrying around a second monitor would be troublesome.

I've seen apps like DisplayPad and AirDisplay, which seem really useful. Unfortunately, all of the ones I've seen require you to be on the same Wifi network. This is a problem for me; quite often I use my iPhone's 4G network or have no network at all.

So, basically I'm looking for an app that will extend my desktop onto my iPad as a second screen over either Bluetooth (though I feel this may be too slow) or over my USB/Lightning cable. I've seen TwomonUSB, but currently that is Windows only.

Are there any other solutions out there?
Bluetooth is not possible:


  Bluetooth does not provide enough network bandwidth, or throughput, to be able to support Air Display.


If the device is jailbroken, you can tether the device to your computer over USB and use Air&nbsp;Display this way.


Install Air Display on both OS X and iOS.
Install MyWi and connect the device to OS X using USB.
Turn on USB in MyWi.
Select the device from Air Display's list of available devices.