This was taken from the Tech TV site.
"A startup program for every user
There's a startup program for eash user, too. In the bash shell, modify the user's ~/.bashrc file. (Note that tcsh uses the ~/.tcshrc file.) You'd most commonly use these files to add command line aliases, modify prompts, and the like, but any shell command can be placed there. "
That's probably what you want. Just put in the command to launch the app, and when they login, it should automatically go. The link at the top provides some additional ways that may be helpful to you.