AstroHQ presents a hardware means to turn the iPad into a full-on second Mac display-- the Luna Display, a tiny dongle allowing users to connect the tablet to their PC or notebook, wire-free.
The Luna Display plugs into the Mini DisplayPort or USB-C port found in modern Macs and MacBooks. It works together with a companion app on both Mac and iPad, using wifi to transfer data between the two.
According to AstroHQ, the hardware dongle taps into Macs' full graphics capabilities, including Metal GPU support. As such, it promises very high image quality with full Retina resolution and reliability across all visual media. One can also use the iPad touchscreen, with pinch to zoom, scrolling and even Apple Pencil support.