FUJIFILM X RAW STUDIO Ver.1.1 is now available, on mac, but now also for windows.
(1.1 also adds support for the X-H1) One has to attach the same camera to the computer by with the photos are taken and then you can emulate the same actions on your PC as you could perform with the in-body RAW conversion. Clear advantage is that you can convert all RAF's on your storage and it is a bit WISIWIG. A bit clumsy interface. It works OK, but could be much nicer.
Personally I do not see much use, but if you are a JPG shooter or maybe RAW+JPEG you can very easily test which in-camera settings are best to your liking. And . . . .
It is free!
You can download the code from: