Originally Posted by ilovejedd
On my ICS/JB tablets (Asus Nexus 7, Toshiba Excite 7.7, Asus Transformer Infinity, Ainol Novo7 Venus), the fullscreen option just dims the navbar but doesn't get rid of it. I remember fullscreen working before on Gingerbread but on ICS/JB, it seems the only way I'd be able to get rid of the navbar is with a custom ROM.
Try the app GMD Gesture control
It requires root access, but merely a matter of five minutes work, if that. No custom ROM required. With the app, you can hide the status bar, and use gestures instead. There's an attached video demoing the app, and at the 30s point the status bar is hidden.