Comparison

CrowdMag vs O

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

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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 .

About

O

Features
Read full description

Some of the main features of the application are: • Calculator: easily define what the geometrical parameters for rock blasting should be. • Safety: Measure the ground vibration and acoustics levels of the blast site. • Data tables: Find out acceptable levels of vibration, glossary used in the explosive industry, linear charge of the explosive according to different diameters and desities of explosive and etc. • Products: Learn more about the range of solutions O-Pitblast can offer you to optimize your drilling and rock blasting solutions.

Screenshots

CrowdMag4 screens
O4 screens

Verdict

The call

The clearest difference is ads: CrowdMag at none against O's shown. O's advantage is update cadence (every 2 weeks vs every 2 months) and iOS requirement (12.0 vs 15.0). On price, in-app purchases and device support 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

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

CrowdMag ships an update every 2 months, O every 2 weeks. The most recent releases landed on September 22, 2026 and September 14, 2026 respectively.

Scorecard3 real differences · 7 level
CrowdMag versus O: the parameters behind the verdict, then further details
ParameterCrowdMagO
PriceFreeFree
Rating4.3 (24 ratings) — better—
Positive reviews52.9% of reviews—
Number of ratings24 — better—
Update frequencyEvery 2 monthsEvery 2 weeks — better
AdsNo — betterYes
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size18 MB52 MB
Age rating4+4+
DeveloperUniversity of Colorado BoulderO-Pitblast, Lda.

In-app purchases

None

CrowdMag

No in-app purchases

None

O

No in-app purchases

Questions

Is CrowdMag free?
CrowdMag is free to download, with no in-app purchases.
Is O free?
O is free to download, with no in-app purchases.
Do CrowdMag or O have ads?
O shows ads; CrowdMag does not.
Which is updated more often, CrowdMag or O?
CrowdMag ships an update every 2 months, and O every 2 weeks. Most recently, CrowdMag was updated on September 22, 2026 and O on September 14, 2026.

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