There is no "Shepherd" software, per say, but I use ExBal on the PC, and with my PDA, to compute trajectory tables for them. http://www.perry-systems.com/index.html
I took it one step further, and came up with a yardage value for the top, middle, and bottom of each circle, to give me more aiming points. Can't seem to get a picture of my range card to post...If you are interested, I will be glad to share all my data.
I used them with good success, to take groundhogs out to 500 yards, and a deer at a (lasered) 808 yards. Poor fella didn't even know I was in the same Zip Code.