Fold Angle: Hinge Protractor

Your folding iPhone already knows how far it's open. Fold Angle turns the hinge into a protractor. Set the phone into a corner, against a door, or over the edge of a box, and read the angle between the two halves in degrees. Tap once to hold a reading, then lift the phone away and read what it captured. Set any angle as zero to compare two corners, or to measure how far a door swings. A light tap every 15° and a firm one at exactly 90°, so you can feel square without looking. Built for iPhone Duo. On other iPhones it works as a tilt meter using the motion sensors. No ads, no tracking, no data collected. For quick everyday checks rather than calibrated precision work.