Full-screen mode lets you view more of the screen by tapping the Full-Screen icon to remove the BaconReader header.
Full screen mode is represented by an icon with four arrows in the lower right hand corner of the screen. Tap this icon to toggle full-screen mode on/off.
If you do not wish to use Full-Screen mode, you can de-select the "Full-screen mode" checkbox in the app Appearance settings. Then this icon will not appear onscreen.