How to Program. The way you program them is special. You use the app Notepad as the display and let the device print a menu that you can choose from. Make sure you use EN_US keyboard layout for this. To enter setup mode, press the iwit dial while you plug it to a computer via USB. You should have Notepad already open and in focus when you do this so that Notepad receives all the key output from the iwit. The rest is simply to navigate the menu with the dial itself. Each can be programmed to give different keystrokes independent of each other and thus you can connect multiple iwit knobs and have them control different things (a bit like Palette ($330 for a Travel Console)). This is what the Surface Dial can't do, as multiple devices would only map to the same Dial API. The same goes for ordinary USB volume controllers, since all of them would map to the same volume +/- mute keys.
Granted, this setup UI is not the most user-friendly, but it gets the job done. If you prefer a more user-friendly setup procedure, you probably would prefer a TourBox ($158) or a designer keyboard ($90). Taobao users would have more options like this keyboard (RMB 399 = $56) or this dial (RMB 138 = $20) that allow custom key assignments. Iwit also offers a larger video editing controller (RMB 799 = $113) at Taobao featuring a knob, a shutter ring and a dial (see photo right), but again you have to deal with their special setup UI.
Mutiple Devices working together
That said, the only missing piece from my standard keyboard is a dial. Or, a few dials. So, I put the two iwit dials besides my keyboard. Because they are wired and the connectors stick out, I can only put them side-by-side. One knob controls Brush Wetness (hotkeys Q W) and the other Pigment Adjuster (hotkeys , .). And I still have more assignments available for operations of knob short press, long press, and knob rotation while pressed. So, a total of 6 assignments per controller.