Fuji RAW Studio
If you have a Fuji camera like the X-Pro 2 or a X100, there is a interesting application for OS X and Windows called Fuji RAW Studio.
It is very interesting. What it does is to give you a way to take raw files you have on your hard drive and process them through your Fuji camera as if you did it on the camera.
The advantage to this is that you can use their awesome presets, and jpeg engine. But the limit is that you can only process the raw files using the same hardware they were shot with.
I use it when I change my mind about a preset, later on. My current process have changed from only shooting raw and using Lightroom to shooting JPEG + RAW and just importing JPEGs out of the camera into photos. And if I want to change something I re-process using RAW Studio.