No need for this program, you can do the same thing from the terminal.
Enable voltage meter:
touch /Volumes/(the name of the iPod)/iPod_Control/Device/_show_voltage
Enable battery display:
rm /Volumes/(the name of the iPod)/iPod_Control/Device/_show_voltage
Make sure you replace "(the name of the iPod)" with the name of your iPod.
Be sure to add a backslash before spaces and other special characters. For example, if the name of your iPod is "My Sweet iPod" then you'll need to type "My\ Sweet\ iPod". Similarly, "Bob's Music Thingamajig" would be "Bob\'s\ Music\ Thingamajig". If yours is named just "iPod" like mine is, then there's no special rules.