Lo Ban AR: Ruler, Compass

A measuring toolkit for carpenters, builders, and anyone renovating a home. LO BAN RULER — AT TRUE SCALE Three rulers built from the original specifications: 52.2 cm, 42.9 cm and 38.8 cm. Enter a measurement and the app shows which segment it falls into on all three rulers at once. What makes it different: the scale on screen is drawn at true 1:1. One centimetre on screen is one centimetre in the world, computed from the physical size of the device in your hand. A calibration screen using a bank card lets you verify it yourself. Edge mode pushes the scale to the very edge of the display so you can lay an object against it. Two-step plus and minus buttons sit either side of the number field, with hold-to-repeat — no deleting and retyping a long number because you were off by a millimetre. HEADING COMPASS A multi-ring dial built after traditional instruments, read from the outer ring inward. Drawn at high resolution and scaled down, so it stays sharp when you zoom. Two colour sets to choose from. Devices without a magnetometer still work fully: type the heading in and every ring still resolves. CALENDAR Lunar and solar calendar, public holidays, and your own events. Notification reminders, with lunar-date recurrence so annual observances do not drift. MEASURE WITH THE CAMERA No ruler to hand? Point the lens instead: mark two points in the room, the app estimates the distance between them and reads it against all three rulers. Every measurement carries an error band, and the app says plainly when a figure is not firm enough to settle a segment — when the band straddles a boundary, or when one end of the line landed on a surface the app inferred rather than saw. It will not settle on a number it does not trust itself. When you need a firm figure, the physical ruler and the number pad are both still there. Camera access is only requested when you tap this measuring button, and declining locks nothing else. ABOUT Free. No in-app purchases, no ads, no account required. Works offline — every calculation runs on the device. The app collects no data and sends nothing off your device. Details in the privacy policy.