There are several ways to start a program at boot time, the 'best' depends on the 'character' of the app: Is it more of a real deamon or is it an interactive GUI'ed Application every user should be provided with? For StartupItems being 'deprecated' ( as i read the offical apple documentation ) you maybe could use just the recommended launchd.
For launchd you need a .plist, which is an XML file, incorporating the name and the path to your app. You could use this example as a template:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>YourAppsName</string>
<key>Program</key>
<string>/usr/local/sbin/Your.app</string>
<key>ProgramArguments</key>
<array>
<string>/usr/local/sbin/Your.app</string>
</array>
<key>RunAtLoad</key>
<true/>
</true/>
</dict>
</plist>
Place this file under /Library/LaunchAgents/com.yourname.YourApp.plist using sudo (you will need administrator privileges) and assure that it's being owned by root:wheel (which should be the default moving it with 'sudo')
More details, especially about the PropertyList's options, are under
http://en.wikipedia.org/wiki/Launchd
Next, use the launchctl command in terminal to load it:
Code:
sudo launchctl load /Library/LaunchAgents/com.yourname.YourApp.plist
In case of your app needing some special arguments it could become necessary to wrap the program start in a shell script. Then you have to replace the path to Your.app in the .plist file with the path to your start script.
If you prefer the StartupItems way i recommend the article
http://developer.apple.com/document...tartupItems.html#//apple_ref/doc/uid/20002132
There are some tools out there which will help you to set up a 'launch at boot time app'. Two of them which will give you a nice GUI, you'll find under
http://www.codepoetry.net/products/launchdeditor
or
http://sourceforge.net/projects/lingon/files/