As of now that is not officially in iOS. It would mean some kind of ux switch when the keyboard (or trackpad?) is attached. Instead if just touching the app to run you would select by swiping a trackpad left or right, then clicking to open.I think iOS will get that, and it needs it. Until then you need to use your finger as a touch/select and scroll input which isn't idea for a vertical screen.
11/16/15 at 4:53pm