This tool allows you to generate a set of files that will replace your stock weapon crosshairs. This means that you can assign any crosshair to a specific weapon, not just the weapon slot. Please note that you should have cl_crosshair_file set to "" (empty, just double quotes) in order for this script to work.
The original idea and way of implementing this can be found here.
For manual crosshair scripts reference see this page.
This tool will only replace crosshairs for the weapons you pick - all the other ones will remain unchanged.
Please notice that if you are using no explosion smoke script, you should remove it from your custom files and use "Explosion effect" field below to pick the desired effect. You can also pick different effects for each explosive weapon.