CrowdMag vs StraboField
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CrowdMag
This app allows users to measure and contribute to scientific research on Earth's magnetic field using their smartphone. It offers features for recording magnetic data during various activities, including flights, and provides tools for data visualization and analysis.
- Measure magnetic field data
- Contribute to scientific research
- Record data during flights
- Visualize data on maps and graphs
- Magnetic calculator with WMM2020
- Live magnetic compass
- Export data via email/Google Drive
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Introducing CrowdMag's newest feature: Flight Mode, which lets you contribute to scientific research by measuring the magnetic field as you fly around the world. To get started, simply provide your itinerary on the CrowdMag app, and you'll be able to turn your flight into a scientific expedition. Check out this step-by-step tutorial for measuring data while flying: https://geomag.colorado.edu/crowdmag-flight-mode-tutorial . CrowdMag is an app that lets you measure the local magnetic field using your smartphone. You can view the data as a graph or a map in nanotesla units. CrowdMag measures the Z (downward component), H (horizontal intensity), and F (total intensity) magnetic field components. You can use CrowdMag for measuring magnetic data during outdoor activities, while flying, or to conduct your own experiments. You can also share it with NOAA to help scientists better understand Earth's magnetic field. If you're going for a walk, run, or other outdoor activities, you can use CrowdMag to measure the magnetic data along your path and save it as a "magtivity." And, if you get a new phone, don't worry! You can export a backup of your CrowdMag data and save it on your computer. This way, if you have to reset your phone or switch to a new one, you can import your backup and continue using CrowdMag without losing your data or progress. CrowdMag also has a magnetic calculator that provides magvar (declination), the magnetic field's dip angle, total magnetic field, and other magnetic field components based on the latest World Magnetic Model (WMM2020). Some of the other features of CrowdMag include creating your own magtivities, customizing recording frequency and location accuracy, exporting your data via email or Google Drive, and seeing generalized crowdsourced magnetic data from other users. And, before we forget, CrowdMag also features a compass that distinctly shows both true and magnetic north. As an added feature, the compass also has a 3D display with an optional audio output - check it out! CrowdMag features: * Create your own magnetic activity (called a "magtivity") * Measure data while flying * Customize recording frequency and location accuracy to your preferences * View your magnetic data on an interactive Google Map * Graph your data as a time series line chart * Check the quality of your data by comparing it with the World Magnetic Model (WMM) * Export your data as a CSV file * Clear stored data on your phone when you want to start fresh * Choose to share your data with NOAA (optional) * See generalized crowdsourced magnetic data from other users * Use the live magnetic compass for 2D and 3D rendering * View information about the current solar magnetic disturbance * Use the most up-to-date magnetic field model (WMM2020) * Export your data via email, Google Drive, or other options * Export a CrowdMag backup to save your contributions' status and data * Import your CrowdMag backup (works across different phone platforms) Visit https://geomag.colorado.edu/crowdmag to see crowdsourced magnetic data .
StraboField
This mobile application helps geologists record field observations, capture data like photos and sketches, and create geologic maps. It supports various geological subdisciplines and allows for offline use with data syncing capabilities.
- Record field data with photos, sketches, and notes
- Collect georeferenced orientation and spatial data
- Use custom or built-in basemaps offline
- Create multi-scale observations with nested Spots
- Organize and back up data locally or to StraboSpot.org
- Fully functional offline for remote fieldwork
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StraboField is a powerful, all-in-one mobile app designed to streamline your geological fieldwork. Record observations, capture photos and sketches, collect orientation data, create geologic maps and stratigraphic sections — all from a single, map-centered platform. Easily collect spatially referenced data using point, line, or polygon-based Spots. Work across multiple scales using nested Spots and high-resolution image basemaps. Designed by geologists, for geologists, StraboField supports workflows across subdisciplines including structural geology, sedimentology, petrology, volcanology, and geomorphology. ** Key Features: ** * Capture field data with photos, sketches, and notes * Collect georeferenced orientation and spatial data * Use custom or built-in basemaps offline * Create multi-scale observations with nested Spots * Organize and back up data locally or to StraboSpot.org * StraboField is fully functional offline, making it ideal for remote fieldwork. Once online, your data can be synced to the StraboSpot digital data system at StraboSpot.org — an open- source platform supported by the National Science Foundation.
Screenshots
Verdict
The clearest difference is update cadence: StraboField at every 2 weeks against CrowdMag's every 2 months. StraboField also leads on rating (4.5 vs 4.3). On price, review sentiment, ratings volume and ads 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.
StraboField holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 24 and 19 respectively. Written reviews complicate that: 53% of CrowdMag's written reviews are positive against 50% of StraboField's, so the app with the better star average is not the one people write more warmly about.
CrowdMag ships an update every 2 months, StraboField every 2 weeks. The most recent releases landed on September 22, 2026 and September 18, 2026 respectively.
| Parameter | CrowdMag | StraboField |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (24 ratings) | 4.5 (19 ratings) — better |
| Positive reviews | 52.9% of reviews — better | 50.0% of reviews |
| Number of ratings | 24 — better | 19 |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 18 MB | 87 MB |
| Age rating | 4+ | 4+ |
| Developer | University of Colorado Boulder | The University of Kansas |
Customer experience
CrowdMag
StraboField
In-app purchases
CrowdMag
No in-app purchases
StraboField
No in-app purchases








