Clinometer + bubble level v2.2 is the best and most accurate Android level app. This is the first version, which has two unique ratings. With this program you can even calibrate your device even on non-smooth surfaces.
✔ High resolution graphics
✔ Redesign (modern) application navigation
✔ New theme with slim frame (Previously still selectable)
✔ New unit mode 1V: H common in engineering
✔ Tagged roofed mode: 12
✔ Camera mode and relative angle
According to Wikipedia: A tool to measure the angle of a gradient, height, or height of an object according to gravity. This device is called inclinometer, tilt indicator, slope gauge, gradient meter or gradiometer, level gauge (or level meter), and deviation declinometer. The slope can be upward slopes (positive slopes, ie the slope viewed by the viewer from the bottom up) and downward slope (curve slope, the slope of the viewer when viewed by the viewer from top to bottom Looking down).