I've tried starting a full screen application without a window manager, using xinit, which works but instead of starting at the top left of the screen the application starts somewhere in the middle of my screen.
I've tried the same using a custom entry in /usr/share/xsessions and starting that from lightdm instead of the default ubuntu window manager, but that gives me the same result.
I've then added my application to the startup applications of the ubuntu window manager and that works properly... but I don't want to start the entire desktop
So I'm thinking perhaps a simple window manager will allow me to define that my application should start as soon as it is loaded and that as a result it will be displayed full screen and starting at the upper left corner of the screen.
So basically a Window Manager that will allow me to disable everything except my application. (And the background should be completely black by default so that the screen is black until my application has finished loading