I was playing with the text to speech functions in Settintgs>Accessibility last night and somehow I have rendered the iPad largely (but not wholly) unresponsive. I don't mean that it does not respond to the usual gestures; I expected this when I enabled these functions and for a while it seemed to be working fine with the altered gestures (ie double click to select/deselect something). What has happened is that the screen has become almost, but not entirely, unresponsive. Tapping/double tapping a folder does not open it. Tapping/double tapping an app, including the Settings app does noting so I can't get back into settings to undo whatever it is I've done. Touching and holdind an app similarly has no effect. A four finger upward and downward swipe will reveal the recently used apps but tapping/touching and holding/swiping with any number of fingers also has no effect. Opening and closing the smart cover turns the iPad on and off but atteppting to turn it on and off using the power button gets me to the screen where it tells me to swipe the slider to power up/down but the screen does not recognise it when I attempt to swipe. Notably there is now also a rectangle approximately 0.5 cm x 2.0 cm that has appeared near the corner on the long side of the iPad to the left of the Home button. This rectangle doesn't seem to do anything when tapped, swiped or held. The display continues to shift from landscape to portrait view when the iPad is rotated but the newly appeared rectangle does not rotate with the rest of the display but stays where it is with reference to the Home button. Can anyone tell me what I have done and how I can undo it? This is immensely frustrating!