Sorry for the delayed response.
For the image "Into white" and others similar to it that you may find, I used an old app called Fractal Explorer. It is no longer being developed but is still available on a number of third party download sites. If you do a web search for "Fractal Explorer 2.02" a number of these sites will come up and seem to be "safe" from my experience. It comes with examples to play with and is fairly intuitive.
It is a Windows app but I run it on my Mac Pro using a Windows emulator called Wineskin.