This is a modification of a modification (yup, really) of AppleWirelessKeyboard utility by uxsoft.

The original utility is great, the modification by gered is even more awesome.

BUT. There is always some BUT.

The app:

• is poking around in tray
• is awkwardly sitting in "Apps" in the Task Manager, instead of "Background processes"
• has really UGLY OSD GUI, bleh
• wtf why does it use CoreAudio API instead of just emulating native multimedia keys presses?

So my modification:

• uses native multimedia controls, so you get 👇 THIS NATIVE OSD instead of their fucking ugly custom GUI bleeh
  
• adds ability to run it without tray icon and without hooking the bullshit F3 and F4 keys, because they are as useful as third nipple
  
• makes it not fucking poke around in task manager
• adds one settings to reverse the behaviour of Fn emulation
  

Better go see the gered/AppleWirelessKeyboard repo for the most accurate and latest information about it.