An irreplaceable tool at the construction site. If you decide to build something, start repairing, or just want to hang a picture, then without iPhone now it is impossible to do this. And all because for our telephone there is a miracle program that shows how your eye differs from the perpendicular to the straight line passing through the center of mass of the earth. And everyone can determine their own coefficient of congenital curvature. It is only better to do this before you start laying tiles. The program determines the angle to the horizon horizontally and vertically, it is possible to make a zero calibration. 
Install from AppStore
