It meets my needs, with a little acceptable flaw.

I use my win8.1 notebook, and use iPad Air 2 as the second screen by TwomonUSB. It works perfectly, without any complex setting. The only problem is the display on iPad has slightly short delay, so lower quality increases as the FPS increases. That means, it isnt ideal for YouTube videos, but for relatively static objects. In my case, I put journal articles on that for reading, so its not a big deal for me. This app is for people who needs to use iPad as the second screen to display documents, so they could read those documents while typing text on the first screen. Otherwise, for comparison.

Sora Taneshima about TwomonUSB - Extended Display