I too was annoyed by the seeming lack of full-screen support for existing notes, but there is a button on your second screen shot, that allows you to get full-screen back. Of course since it's iOS7, it doesn't look like a button. You want to click on the pair of 45-degree-angle arrows, just to the left of the title. A competely non-obvious icon choice, made worse by the lack of a visible button-ness, but there ya go. Welcome to Apple's brave new world where you blindly click on every part of a UI until you find something that reacts.