Please, try this if u have device with soft keys (ice cream sandwich):
1- make a very simple 2d project (ie: an empty one) - Portrait
2- add anything to be displayed (ie: an image)
3- run the build, use the soft keys: (press “Home” button first - then bring our app back again by pressing the “Recent” button)
You will find the screen flipped vertically
Tried with:
unity ver: 5.3.4p5
os: 4.0.3 (ice cream)
tablet: Huawei mediapad 7 lite