Readius vs Magnetic Sensor
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Readius
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全数字掌上式彩色多普勒超声显像仪 本应用配合Readius L8、C3、C6探头使用,在做医疗决定之前,还应寻求医生的建议。
Magnetic Sensor
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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.
Screenshots
Verdict
The clearest difference is ads: Readius at none against Magnetic Sensor's shown. Magnetic Sensor's advantage is update cadence (fortnightly vs every 2 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Readius ships an update every 2 months, Magnetic Sensor fortnightly. The most recent releases landed on October 27, 2026 and October 7, 2026 respectively.
| Parameter | Readius | Magnetic Sensor |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 2 months | Fortnightly — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 14 — better | 15.1 |
| Further details — not scored | ||
| Size | 418 MB | 25 MB |
| Age rating | 17+ | 4+ |
| Developer | Shantou Institute of Ultrasonic Inst. Co., Ltd. | Seonggon Sim |
In-app purchases
Readius
No in-app purchases
Magnetic Sensor
No in-app purchases
Questions
Is Readius free?
Is Magnetic Sensor free?
Do Readius or Magnetic Sensor have ads?
Which is updated more often, Readius or Magnetic Sensor?
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