Grid Tool

[Frank]

Code:

var opt = document.createElement("option");
opt.value = parseFloat(prompt("1/?")/4);
opt.text = "1/"+String(opt.value*4);
document.getElementById('grid_select').add(opt)

Shoutout to WS3 schools for helping me with the HTML library and stuff.
Jacob_ could potentially add more options to the grid select or even enable custom values.
For this tool, input the number of bold lines you want per measure. For reference, 4 is the default for normal OS.