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Built for Duo

Angle Gauge

Measures angles to 0.1° using the iPhone Duo hinge, with target, match, and level tools.

Jared Kaeb · Utilities · Free

View on the App StoreSave

iPhone screenshots

Angle Gauge — iPhone screenshots 1
Angle Gauge — iPhone screenshots 2

How it uses iPhone Duo

Angle Gauge turns the hinge of iPhone Duo into a precision protractor. Set the phone into a corner, against two surfaces or

App Store descriptionWritten by the developer.

Angle Gauge turns the hinge of iPhone Duo into a precision protractor. Set the phone into a corner, against two surfaces or across a joint, and read the angle to a tenth of a degree. MEASURE • Live angle to 0.1°, on the inside display or the outside one • Hold, Auto-Hold when the reading settles, and Zero Here for relative angles • Supplement, bisect and miter angle for every reading • Snap to 1°, 5°, 15° or your own step TARGET • Pick 45°, 90° or any angle with presets and a fine stepper • Haptics build as you get close, then click when you arrive • Tolerance from ±2° down to ±0.25° MATCH • Capture angles into a named library • Find them again later, by feel LEVEL • Bubble level when the phone lies flat, line level on its edge • Two-step calibration cancels the camera bump and the slope of your table • On iPhone Duo, read the hinge relative to true level ON EVERY IPHONE The level works on any iPhone. Measure, Target and Match read the hinge, so they need iPhone Duo with iOS 27.1 or later. BUILT LIKE AN INSTRUMENT • Two-point hinge calibration against fully closed and flat • Degrees, radians or percent open • VoiceOver, Reduce Motion, light and dark • No accounts, no ads, no tracking, and it never goes online

Angle Gauge on iPhone Duo: FAQ

Is Angle Gauge optimized for iPhone Duo?

Yes. Angle Gauge is Built for Duo: it uses the fold, Split View or the outer display. Verified on October 25, 2026 (App Store text).

What does Angle Gauge look like on iPhone Duo?

Angle Gauge turns the hinge of iPhone Duo into a precision protractor. Set the phone into a corner, against two surfaces or

How much does Angle Gauge cost?

Angle Gauge is free to download on the App Store.

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