Here is tutorial code for the UIScreenEdgePanGestureRecognizer for left/right edge swipes on iOS.
You can only add one edge to the UIScreenEdgePanGestureRecognizer. If you want to respond to multiple edges, add a separate gesture recognizer for each screen edge. Use the UIRectEdge to setup each gesture recognizer in your app.
If you want to use multiple gestures in-conjunction with the UIScreenEdgePanGestureRecognizer, you'll have to set the delegate and conform to the UIGestureRecognizerDelegate protocol