I can’t vouch for android, but on iOS if you turn your device upside-down then the game should rotate 180 degrees so everything still appears right-side-up. Currently the app never rotates so if you hold your device with the home button at the top then the game will appear upside-down. Other apps and games rotate with the device. When my iPad is plugged in, I use it so the plug comes out of the top in order to avoid damaging the cable.
This has been mentioned as a feature request before: Rotate Screen 180 Degrees. I think this is a bug since every other app does it and it is expected behavior for the app to rotate with the device.
Edit: I had a friend check on android. On android no apps will flip upside-down when you rotate the device 180 degrees. On iOS all apps will flip upside-down.