iDisplayMate is utility app that allows your Mac to be used as second monitor for the other Mac via WiFi network!
With iDisplayMate you can work more effectively. Using Mac as extra display can increase productivity for engineers, designers, and artists!
-Download iDisplayMateServer for your Mac.
-Connect two Mac to the same WiFi network.
-Run iDisplayMateServer& select "Start Virtual Display" in menu.
-Run iDisplayMate for the other Mac.
iDisplayMateServer for Mac download link:
Didn’t work and made me pay twice
The installation instructions were confusing and seemed to require that I buy the app twice (once for the Mac and the other for the iPad). Even after that fiasco, the app didn’t work at all. Every time I opened the server app, it asked me to update the app. Then, when there eventually did seem to be some connection between the Mac and the iPad, the iPad screen stayed blank. All-in-all, a poor experience. I got my money back.