With the horizontal calibration added to ios, I put my mobile phone on a flat desktop, and the display result is like this. How to calibrate?

-1 Not tried. Let's see if it's not set properly. In the compass of IOS7, the calibrated slide screen has a gyro level test function, and then the iPhone can be placed flat on a flat thing to get the answer. If it is 0, then your iPhone is fine, and it should be a problem that IOS7 has not fixed! I don't think it makes sense for the landlord to insist on this.

Or change

Level (iHandy level) 1.6 1.0

This kind of software should be fine, like a plumber.