Support

Questions, bugs or ideas? Email me at pierre@lab108.de. I usually reply within two working days.

Helpful to include: your iPhone model, iOS version and – for a bug – what you did before it happened.

Step-by-step guides for every feature are also in the app under Settings → Help → Guides.

FAQ

How do I get an exact right angle off a wall?

Angle → Plan view. Lay the iPhone flat with its long edge flush against the wall and tap "Set reference". Then lay it flat on a straightedge or along the string line and turn it until the reading turns green and the tone holds steady.

How accurate is the app?

Tilt ±0.1° after calibration, plan ±0.3–0.5° short-term, AR distance ±1 cm per metre, height ±5–10 mm. An error of 0.5° is already 2.6 cm over 3 m, so always verify important measurements, e.g. with the 3-4-5 check in the app.

The plan angle drifts over time.

The gyroscope drifts slowly. After about a minute the app shows a hint. Put the iPhone back against the wall and tap "Reset reference".

The level doesn't read 0.0° on a flat surface.

Calibrate once: Settings → Calibrate. Lay the iPhone flat, record the first side, turn it 180°, record the second side. The surface need not be level, only stable. Recalibrate after changing your case.

Height and AR measure don't work or are inaccurate.

These features need camera access (iOS Settings → 90° → Camera) and work best with LiDAR (iPhone Pro models from iPhone 12 Pro). Move slowly, make sure there is good light and tap "Check reference" now and then to correct drift.

How do I set an excavation target in Height?

Measure → Height → aim at the reference mark → "Set reference mark" → "Excavation". Enter the mark above finished floor (usually 1.000 m) and the depth in mm. With 250 mm the excavation level is 1.250 m below the mark. The app then shows "dig deeper" or "dug too deep" in cm.

Can I turn the tone off? It plays in Silent Mode.

Yes: Settings → Feedback → Tone, or tap the tone indicator in plan view. The tone deliberately plays in Silent Mode so you can hear it on site.

Is my data stored or transmitted?

No. There is no account and no tracking. Saved measurements stay on your iPhone. Details in the privacy policy.

I'd like a refund.

Purchases and refunds are handled by Apple. You can request a refund at reportaproblem.apple.com.

Note on measurement accuracy

90° uses the iPhone's sensors and does not replace calibrated measuring instruments. Readings can vary with the device, calibration, environment and handling. Always verify measurements that components, safety or costs depend on with suitable tools.