I upgraded to iOS 7 after GM and I enabled this thing where the phone reads your text when you select it. For some reason I was just using my phone and this blackbox appeared and when you press on anything the blackbox goes on it and reads it. The first time, I waited and it disappeared and let me use my phone properly. The second time randomly, it appeared again I could barely scroll down on Setting, I turned off voice over through accessibility and it stopped. Now this crap came again. like I can't even use my phone since Ive to click on it many times and wait till the blackbox appears and reads the text.
It sounds like you may have inadvertently re-enable Voice Over with a Triple-Click on the home button. I would recommend taking a look at the article below for more information on Voice Over, as well as how to turn it off.