I created an implementation of Conway’s Game of Life using Unity’s ECS.
You can access the source code in Gitlab.
Licensed under CC-By 4.0 International.
Why?
This was a learning exercise for myself. And I can recommend it, if you are getting started with ECS.
The whole simulation is a single System calculating the state of a Cell based on the previous state of its neighbors.
Disclaimer: the actual implementation is not really cache-friendly 
I documented the steps I took during the development, if you are planning on re-creating this for learning.