Here is a simple simulator for a single bitgrid cell. There are 4 bits input from the neighbors, which results in an index between 0 and 15. Each possible combination has a bit in the look up table (LUT), which then feeds an output bit to a neighbor.
Index (Hex): 0
Each possible input combination links to one of these checkboxes. The current input is marked with an asterisk (*).
LUT (Hex): 0
This is the resulting value from all of the bits you entered, in hexadecimal
LUT Description: nop
So, the above is all a first pass at things, it's all open source, the github repository is at https://github.com/mikewarot/Bitgrid_C