Comparison

Sensor Logger vs Magnetometer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Sensor Logger

This app collects and displays data from various device sensors, including motion, GPS, and audio. It offers background recording, interactive plots, and multiple export formats. Advanced features allow for data streaming, systematic data collection from other users, and creating shareable data-driven dashboards.

Highlights
  • One-tap logging
  • Background recording
  • Interactive plot visualization
  • Data streaming (HTTP/MQTT)
  • CSV, JSON, Excel, KML exports
  • Create and share data dashboards
  • Systematic data collection studies
Features
Read full description

Sensor Logger collects, records and displays data from a range of sensors on iPhone, Apple Watch, iPad and AirPods — including accelerometer, gyroscope, GPS, audio, camera and Bluetooth devices. You can log device properties such as screen brightness, battery and network state. Select and preview desired sensors in a few taps. A single tap initiates the recording function, which works even when the app is in the background. View and manage recordings within the app via interactive plots. The app supports many export formats, including Zipped CSV, JSON, Excel, KML and more. For advanced use cases, stream data via HTTP or MQTT, resample measurements from multiple sensors, create Studies to collect data from other users systematically and write custom automation rules based on sensor, time and location. Once you have collected your data, you can create Stories — data-driven dashboard with your recordings, hosted online for effortless sharing. Sensor Logger is designed for researchers, educators, and anyone interested in collecting or monitoring sensors on their smartphone. It serves as the ultimate toolbox for exploring various fields, including physics, science, technology, engineering, and mathematics (STEM). - One-tap logging - Background recording - Recordings on interactive plots - Stream data via HTTP & MQTT - Intelligent, custom rule engine - Zipped CSV, JSON, Excel, KML & SQLite exports - Resample and aggregate measurements - Enable & disable specific sensors - Scan and log nearby Bluetooth devices - Add timestamp-synchronised annotations during recording - Adjust sampling frequency for sensor groups - Custom recording workflow - Raw and calibrated measurements available - Live plots and readings for sensors - Organise, sort and filter recordings - Control & track recording session from Watch - Bulk export & delete recordings - Resources to help you analyse your data - Data stays on-device and private - Create and share dashboard-style, data-driven Stories using your recordings, hosted online. Studies & Sensor Logger Cloud Create Studies to collect data from other Sensor Logger users efficiently. When activated, Studies use the investigator's specified sensor configuration for consistent data collection. Participants can upload their recordings to a secure cloud and join, pause, or switch Studies anytime. Studies include clear data usage descriptions, privacy statements, and contact details to ensure privacy compliance. Customize Study size, duration, sensor configuration, and export formats. Optional Paid Features (Plus, Pro & Ultimate) - No limitations on the number of stored recordings - Additional export formats - Combined CSV export - Customise recording workflow - Advanced sensor configurations - Custom naming templates - Theme and icon customizations - Unlimited Bluetooth beacons and no limit on the minimum RSSI - Create larger Studies with more participants - More allocated storage on Sensor Logger Cloud - Email support - Advanced study customization Supported Measurements - Device Acceleration (Accelerometer; Raw & Calibrated) - Gravity Vector (Accelerometer) - Device Rotation Rate (Gyro) - Device Orientation (Gyro Raw & Calibrated) - Magnetic Field (Magnetometer Raw & Calibrated) - Compass - Barometric Altitude (Barometer) - GPS Coordinate, Altitude, Speed & Heading - Audio (Microphone) - Loudness (Microphone) - Images (Front/Back) - Video (Front/Back) - Depth - Pedometer - Activity - Heart Rate (Watch) - Wrist Motion (Watch) - Location & Barometer (Watch) - Annotations (Timestamp and text) - Device battery level and state - Device screen brightness level - Nearby Bluetooth beacons (advertised data) - Headphone Motion (AirPods) - Network Heart rate logging requires integration with the Health app on the watch. Permission to access the heart rate from HealthKit on the watch is needed for the app to log the measurements. Terms of Service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Magnetometer

This application uses your iPhone's compass to detect electromagnetic interference, helping you find metal objects or magnets. It's designed for fun and experimental purposes, not as a professional tool. Discover hidden metal items or simply explore the magnetic fields around you.

Highlights
  • Detects metal and magnets
  • Uses iPhone's compass
  • Measures EMF interference
  • Fun and experimental use
  • Simple user interface
Read full description

Magnetometer is a fun app for finding metal or magnets by detecting EMF interference with your iPhone's compass heading. Find your keys, or just have fun discovering what could be made of metal. Magnetometer is not meant to replace an actual, professional-grade metal detector. Magnetometer presents simple information to the user about the interference experiences. For more scientific data, please turn to other great apps on the App Store. Magnetometer is made for fun and for experimental purposes and is not designed for scientific use. Also, don't drop your iPhone in sand hoping to find treasure; it's risky.

Screenshots

Sensor Logger4 screens
Magnetometer4 screens

Verdict

The call

The clearest difference is price: Sensor Logger at Free against Magnetometer's $0.99. Sensor Logger also leads on update cadence (weekly vs every 34 months) and rating (4.8 vs 4.4). Magnetometer's advantage is review sentiment (86% vs 44%) and in-app purchases (none vs 6). On ads 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

CostPrice · In-app purchases · Ads · Monetization

Sensor Logger is free to download; Magnetometer costs $0.99 up front. Sensor Logger sells 6 in-app purchases, starting at $4.99 per month. Magnetometer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Sensor Logger holds the better App Store score, 4.8 against 4.4. That said, the two scores are not equally well evidenced: Sensor Logger has 111 ratings behind it against 13, so its average is the more settled of the two. Written reviews complicate that: 44% of Sensor Logger's written reviews are positive against 86% of Magnetometer's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Sensor Logger ships an update weekly, Magnetometer every 34 months. The most recent releases landed on October 1, 2026 and September 22, 2026 respectively.

Scorecard8 real differences · 2 level
Sensor Logger versus Magnetometer: the parameters behind the verdict, then further details
ParameterSensor LoggerMagnetometer
PriceFree — better$0.99
Rating4.8 (111 ratings) — better4.4 (13 ratings)
Positive reviews44.4% of reviews85.7% of reviews — better
Number of ratings111 — better13
Update frequencyWeekly — betterEvery 34 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, Apple Watch — betteriPhone
Requires iOS16.416.0 — better
Further details — not scored
Size81 MB2 MB
Age rating4+4+
DeveloperLogger Labs LTDBogdan Gavriluta

Customer experience

Sensor Logger

All ratings111 ratings
Positive95.5%
Neutral2.7%
Negative1.8%
Written reviews9 reviews
Positive44.4%
Neutral22.2%
Negative33.3%

Magnetometer

All ratings13 ratings
Positive76.9%
Neutral15.4%
Negative7.7%
Written reviews7 reviews
Positive85.7%
Neutral14.3%
Negative0.0%

In-app purchases

6 purchases

Sensor Logger

Subscriptions6
  • Plus Monthly$4.991 Month
  • Pro Monthly$9.991 Month
  • Ultimate Monthly$24.991 Month
Show 3 more
  • Plus Yearly$49.991 Year
  • Pro Yearly$99.991 Year
  • Ultimate Yearly$249.991 Year
None

Magnetometer

No in-app purchases

Questions

Is Sensor Logger free?
Sensor Logger is free to download, with in-app purchases available.
Is Magnetometer free?
Magnetometer costs $0.99, with no in-app purchases.
Which has better reviews, Sensor Logger or Magnetometer?
Sensor Logger is rated higher. Sensor Logger averages 4.8 out of 5 from 111 ratings, while Magnetometer averages 4.4 from 13 ratings.
Do Sensor Logger or Magnetometer have ads?
Neither Sensor Logger nor Magnetometer shows ads.
Which is updated more often, Sensor Logger or Magnetometer?
Sensor Logger ships an update weekly, and Magnetometer every 34 months. Most recently, Sensor Logger was updated on October 1, 2026 and Magnetometer on September 22, 2026.

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