Does a plugin effect exist like the following 'Grainy Gradients' based off an image?

[lalosalamanca]

https://css-tricks.com/grainy-gradients/

[Alexolotlechuga]

I am not aware of any plugins that produce any kind of gradient like this. Although you could use the Frosted Glass effect and adjust the parameters to make it noisy and harsh. You can also put a noise layer on top of your canvas with a blend mode. I really like to use this technique in my art. Below is a sample of what that looks like.

[Red ochre]

Not sure about the 'based off image' bit but Gradients galore can do dithered gradients.
In my pack, link in sig.