Running application at login window

Greetings! I have written a AppleScript Studio application that essentially just pops up an agreement box for a user to agree to before using one of our specialized labs. I would like this to load at the login screen similar to how BootPicker or SCUBA loads. Any ideas? I’m guessing this may be an AppleScript Studio limitation. I notice the application physically loading at login, but I never see the window.

Thanks for any advise!!