I've used an app called Air Display to do the same thing for quite a while, but ...

		jakejake on Dec 16, 2014 \| parent \| context \| favorite \| on: Use your iDevice as an extra display for your Mac I've used an app called Air Display to do the same thing for quite a while, but instead of USB it connects over WiFi - which is convenient, but the refresh rate is slow. I used it mainly to have my chat client on a 3rd screen.