Accurate? Not for me. – Dual Level- Review

I tried the level on my desk. In the landscape orientation (using the first bubble level) the app told me I needed to raise the left end of my phone to level the desk but when I switched to the portrait orientation (now using the second bubble level) the app said I needed to raise the right side of my phone. Such disparity in the two levels does not inspire much confidence. And, I could not see a means to calibrate the level.
Review by M_Port on Dual Level-.