Not sure if entirely Ionic related, but I have a problem under iOS regarding screen rotation.
As the app loads, correctly in landscape at start, it makes a content-rotation to the left, and stays until another rotation happens. This causes a black border at the bottom, as the screen is still in landscape, just displays sideways… Once a valid rotation is triggered (landscape left/landscape right), it sets and displays properly. I’ve used the lock-rotation plugin before, but it happens using the shouldRotateToOrientation() method also.
It seems the problem appeared after the update to Cordova 5.x, and only occurs on a real iPad, in simulator it works fine.