Player facing with suggested flank and rear bonuses

One way of achieving this without code, that I have seen recently, is to create a token mapped to whatever grid system the GM uses and colour in the rim/outer edge of the token with a colour.
Whatever majority colour is in direct contact with a foe will be the bonus one can then add to their attack:

Green = Front; Yellow = Flank; Red = Rear(Flank), etc.

Check the books but in a 9square grid with Defender in the Centre, CTRL+LMB(left mouse button) will target and draw a line showing exact squares where attack will move through from an Attacker.

First 3 squares in front of where Defender is targeting someone else, themselves too, are aptly named Front facing.
Next two squares to either side of this facing is Flank(+15).
Next two squares wrapping around the Defender is Rear Flank(+25) and finally the extreme opposite square is Rear(+35) facing.
We lock in facing for the Defender when they either have made an attack already(earlier in the round) or once they’ve been attacked by something.
Special circumstances are made if something is completely overpowering vs pesky mosquito bites by “Minions”, but this works for fast and dirty combat resolution.
The colour coding would help but eyeballing via the targeting line is fair enough.