# CrowdMag vs Whenlyy

The clearest difference is in-app purchases: CrowdMag at none against Whenlyy's 1. CrowdMag also leads on device support (3 vs 1). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. Whenlyy sells 1 one-off in-app purchase. CrowdMag asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 22, 2026 and May 17, 2026 respectively.

## The numbers

| Metric | CrowdMag | Whenlyy |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (24 ratings)](https://appshunter.io/ios/app/crowdmag/id910578825/reviews)** | — |
| Number of ratings | **24** | — |
| Positive reviews | 52.9% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free | — |
| Size | 18 MB | 5 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [University of Colorado Boulder](https://appshunter.io/developer/972210292) | [Erkmen Ergul](https://appshunter.io/developer/1798402976) |

## What reviewers say

### CrowdMag

[App page](https://appshunter.io/ios/app/crowdmag/id910578825)

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:** macOS Compatibility

**In-app purchases:** none


### Whenlyy

[App page](https://appshunter.io/ios/app/whenlyy/id6749324955)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Whenly Premium | $1.79 | one-time |


## Frequently asked questions

### Is CrowdMag free?

CrowdMag is free to download, with no in-app purchases.

### Is Whenlyy free?

Whenlyy is free to download, with in-app purchases available.

### Do CrowdMag or Whenlyy have ads?

Neither CrowdMag nor Whenlyy shows ads.

### Which is updated more often, CrowdMag or Whenlyy?

CrowdMag ships an update every 2 months, and Whenlyy every 2 months. Most recently, CrowdMag was updated on September 22, 2026 and Whenlyy on May 17, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*