HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

There's a suggestion to add an optional grid to the HD mod, similar to the one in the map editor. This function could be added to the middle mouse button, where the DD frame is already located. It would be useful for quickly and accurately calculating the length of paths/mountains/forests/other terrain features for DD movement/flight/fuel (or lack thereof)/visibility range. There are many possible applications.

There's also a question about the DD's jump range. It jumps 9 cells to the left, right, and down in a straight line; but only 8 cells upwards. Is this intentional, or am I mistaken?