The Memory-Map Android app can be launched in either portrait or landscape mode, but it does not automatically rotate when you flip the device. This is a deliberate decision based on use in the field, on foot, in lumpy seas, and on rough terrain. We found auto rotation to be more annoying than it is useful.
To change orientation, all you need to do is close the app (by pressing the "Back" button, not the Home button) and launch it again while holding the device in the desired orientation. Even if the home screen does not rotate, if you hold the device sideways and launch the app it will open in landscape mode.
Please Note: Some phones/tablets do not support the upside-down portrait orientation.