Blender (2.8+) - Low Poly Rock Generator
It was based on an addon that unfortunately hasn't been updated, so I decided to try and write a new one for myself as I needed quite a few low poly rocks.
I don't know Python very well at all, so I had to learn on the fly while writing this. With that, it means this isn't identical to the old addon, but it does the job for me. It's far from perfect.
Option to create a more stylised type of rock by remeshing it.