Space to step the algorithm, r to reset, and click a square to toggle it’s “walkable” status.
I created this as I worked through the excellent A* Pathfinding for Beginners tutorial by Patrick Lester, bless his heart. My app is actually not 100% done, in a way that will make it sometimes not take quite the shortest path.
Note that this demo, as opposed to Patrick’s tutorial, does not allow for diagnol movement (as my final application will use a more zelda-esque movement).