This is what you need to do (I just did it for a prog for myself as well, so this should work)
Go into /Library/StartupItems (that's the one at the root of your HD, not the one in your home directory)
I like to use the command line to do things, but you can do it from the finder as well..
cd /Library/StartupItems
Create a folder for your app
mkdir Rumpus
go into that folder
cd Rumpus
Create two text files
one named Rumpus with the the following contents
#!/bin/sh
##
# Start Rumpus
##
ConsoleMessage "Starting Rumpus"
path.to.rumpus.goes.here/rumpus
The other named StartupParameters.plist with the following contents
{
Description = "Rumpus Initialization";
Provides = ("Rumpus");
OrderPreference = "Last";
Messages =
{
start = "Starting Rumpus";
stop = "Stopping Rumpus";
};
}
Then make the file called Rumpus executable
chmod 755 Rumpus
Then restart your Mac and log in, rumpus should already be running (it will get started as root during the startup process).
I really wish they would make a nice gui to make this process easier for everyone, adding startup progs should be as easy as it used to be.