Is my device's acceleromoter working as it should?

I recently installed Asphalt Nitro, a racing app that supports using the device's "gyroscope" for steering. My device being as cheap as it is, it doesn't have a gyroscope, so I assume Asphalt is using the accelerometer. However, it seems to use the wrong axis. (I have to tilt it back and forth to steer.) My question is, is it the app's fault or my tablet's fault? Here's some test data (assuming horizontal is right-side up, data given in m/s²): Right-side up: X=0 Y=9.8 Z=0 Left: X=9.8 Y=0 Z=0 Right: X=-9.8 Y=0 Z=0 Upside down: X=0 Y=-9.8 Z=0 Flat on the ground: X=0 Y=0 Z=9.8