Foldometer: Fold Angle Gauge

Your fold, measured.

Open iPhone Duo and Foldometer turns its hinge into a precision instrument. Watch the two halves move on screen as you open and close it, read the exact angle between the displays, and feel a gentle tap when you land on a right angle or lie perfectly flat. It's the most fun way to see what your new foldable can do.

Not on a foldable? Foldometer is a beautiful level, protractor, slope meter and camera angle finder for every iPhone and iPad.

HINGE (IPHONE DUO)
• The live angle between the two displays, from closed to fully open
• An animated side view of your device that follows the hinge
• Stand presets for Easel, Upright, Video call, Laptop and Reading, or save your own, with a tap when you reach them
• Set a zero at any position to measure how far the hinge moves
• Record the angle over time, then see a chart with the range and peak speed, and share it as an image or CSV

FOLD GAUGE (IPHONE DUO)
• Rest one half on a surface and lay the other against a second surface
• Foldometer combines the hinge with the motion sensors to read each half's angle from horizontal, even when the first surface isn't level

LEVEL
• Stand iPhone on an edge to read its tilt, shown to a tenth of a degree
• Lay it flat and it becomes a bubble level for any surface
• Turn it on its side and the reading keeps counting, with "2.4° from level" right where you need it
• Hold iPhone against one surface, tap Set Zero, then rotate to the next to read the angle between them

SLOPE AND PITCH
• Show any slope in degrees, percent grade, millimetres per metre, inches per foot or roof pitch
• Set a target such as a 2% patio fall, a ¼ in/ft waste pipe, a 1:12 ramp or a 6/12 roof, and feel a tap when you hit it

CAMERA
• Measure angles you can't reach, like a roof line or a leaning post, by lining up arms over the camera view
• Slopes read against the true horizon from the motion sensors, even if iPhone is tilted
• Freeze the frame to fine-tune

PROTRACTOR
• Two draggable arms on a full 360° scale, with a tick of haptic feedback for every degree
• Tap the reading to flip to the reflex angle

PRECISION
• Flip calibration: take a reading, turn iPhone around in place, take another. Calibrating on its back also corrects for the camera bump or a case.
• Auto-Hold freezes the reading the moment iPhone comes to rest, so you can read it after moving away

LOG AND WIDGETS
• Save any reading with one tap, add notes like "Garage roof pitch", and export everything as CSV
• Home Screen and Lock Screen widgets show your fold angle and newest reading

DESIGNED FOR APPLE PLATFORMS
• Built for iPhone Duo's displays: toolbars and tabs along the side, and layouts that adapt as you fold
• Liquid Glass controls, light and dark appearances, and a layered icon
• VoiceOver, Dynamic Type and Reduce Motion support
• No account, no ads, no tracking. Camera images are never recorded or stored, and your readings stay on your device.

A NOTE ON ACCURACY
Readings depend on your device's sensors and how it's held. On iPhone Duo, iOS reports the hinge angle and decides how often it updates. Foldometer is a general measuring tool, not a medical or safety device.