Android Question Dont display activity screen at all - no layout

Maybe I'm not wording it right in searches.
I have an app that i dont need/want, the activity screen to ever show up.
I assume the options are in the manifest somehow.
No layout is ever created
Everything is a service
Nothing is ever displayed. Just copy a file and close
but the all black, full screen, activity screen shows up even though i'm not loading a layout
How do I make my app(service) start up, do it's thing and user never see's anything?

Thanks,
Scott