See a few video examples of a Unity program that visualizes A* pathfinding in a user friendly way with a tracing option.
Here is a small program that I made for a parallel class project during my first semester of graduate school. At the end of the class project, I decided to continue work on it in order to improve path quality, be more user friendly, and introduce a tracing option.
The program visualizes Sequential A* and Parallel New Bidirectional A* (PNBA).
The biggest achievement of this program is the implementation of the PNBA algorithm as described in PNBA*: A Parallel Bidirectional Heuristic Search Algorithm.