# Magnetic Sensor — Compass • Detector • Logger

> Compass • Detector • Logger (iPhone/iPad app by Seonggon Sim.)

- Source: https://appshunter.io/ios/app/magnetic-sensor/id6764468454 (this page in markdown: same URL + `.md`)
- Developer: [Seonggon Sim](https://appshunter.io/developer/1565259950)
- Category: Utilities, Reference
- Price: Free
- Age rating: 4+
- Requires: iOS 15.1 · 25 MB
- Languages: American English, Korean
- Released: 2026-04-30
- Data updated: 2026-09-03
- User reviews in markdown: https://appshunter.io/ios/app/magnetic-sensor/id6764468454/reviews.md

## What is Magnetic Sensor?

Magnetic Sensor turns your phone's built-in magnetometer into three precise tools:

• Compass — A live, tilt-compensated compass with cardinal direction (N/E/S/W) and adjustable magnetic declination so the needle points to true north, not just magnetic north.

• Metal Detector — Set a baseline reading anywhere, choose Low/Med/High sensitivity, and feel haptic pulses that get stronger as the field deviates. Perfect for finding studs in a wall, screws under drywall, or rebar in concrete.

• Field Logger — Record samples at up to 60 Hz, then export to CSV via the share sheet. Saved recordings stay in the app for replay or re-export.

KEY FEATURES
• Live X / Y / Z axis readings + total field magnitude
• Tilt-compensated heading using the accelerometer
• Magnitude history sparkline + multi-channel chart
• Rolling statistics: mean, standard deviation, RMS, range
• Figure-8 calibration helper with quality indicator
• Min / Max tracking with one-tap reset
• Three sample rates: Slow (500 ms), Normal (100 ms), Fast (16 ms)
• Light / Dark / System theme
• English and Korean
• Unit options: μT, mGauss, nT
• Adjustable smoothing
• Magnetic declination presets
• Haptic alerts for the detector
• Keep-screen-awake while recording
• CSV export with full timestamp + per-axis data

PRIVACY
All sensor data is processed on-device and never leaves your phone. The app does not collect location, contacts, or personal information. Anonymous mobile advertising is used to keep the app free; you can watch a rewarded ad to unlock unlimited CSV sharing for the session.

WHO IT'S FOR
• Hobbyists exploring magnetic fields
• DIYers detecting screws, studs, and rebar
• Students collecting data for physics or geology projects
• Hikers wanting a reliable phone compass
• Anyone curious about the invisible field around them

REQUIREMENTS
A device with a magnetometer (most phones built since ~2013). The app cannot work on devices without one — it will tell you on launch.


## Version history (last 3 releases)

### 1.0.2 — 2026-08-31

Updated internal ad configuration to the latest standard.
No changes to features or screens.

### 1.0.1 — 2026-08-26

Fixed ads failing to load. The number and placement of ads are unchanged.

### 1.0.0 — 2026-04-30

No release notes.

## More apps by Seonggon Sim

- [푸드득 - 메뉴 결정](https://appshunter.io/ios/app/id1520504588)
- [QRboy - qr코드 생성기](https://appshunter.io/ios/app/qrboy-qr/id1565637033)
- [Handheld LED Scroller](https://appshunter.io/ios/app/handheld-led-scroller/id1565645742)
- [미세먼지 체크](https://appshunter.io/ios/app/id1565763424)
- [캣도그 - 유기동물 입양 & 실종동물 찾기 & 구조동물](https://appshunter.io/ios/app/and-and/id1565919554)
- [StarDB - StarCraft Info](https://appshunter.io/ios/app/stardb-starcraft-info/id6474464704)

All apps by Seonggon Sim: https://appshunter.io/developer/1565259950

## Related topics

[magnetic sensor](https://appshunter.io/ios/topics/magnetic-sensor) · [quadrant magnetics calculator](https://appshunter.io/ios/topics/quadrant-magnetics-calculator)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-03.*