# 51知灾害 vs VortexWeather

The clearest difference is in-app purchases: 51知灾害 at none against VortexWeather's 4. 51知灾害 also leads on ads (none vs shown) and iOS requirement (9.0 vs 15.1). VortexWeather's advantage is update cadence (fortnightly vs every 4 months). On price and device support there is nothing between them.

Both are free to download. VortexWeather sells 4 in-app purchases, starting at $4.99 per month. 51知灾害 asks for nothing beyond the download.

51知灾害 ships an update every 4 months, VortexWeather fortnightly. The most recent releases landed on November 3, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | 51知灾害 | VortexWeather |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/vortexweather/id6796505055/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Fortnightly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 53 MB | 66 MB |
| Requires iOS | **9.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [钦荣 翁](https://appshunter.io/developer/1278827536) | [VORTEXWEATHER LLC](https://appshunter.io/developer/6796505057) |

## What reviewers say

### 51知灾害

[App page](https://appshunter.io/ios/app/51/id1592935902)

This application provides comprehensive professional service modules. It has been comprehensively upgraded to offer enhanced functionality and user experience.

**Highlights:** Comprehensive professional service modules, Upgraded functionality, Enhanced user experience, Weather information services

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### VortexWeather

[App page](https://appshunter.io/ios/app/vortexweather/id6796505055)

Access detailed weather data including hurricanes, radar, satellite, and forecast models. Offers free basic features and paid subscriptions for advanced capabilities like 3D viewers and extended forecast data.

**Highlights:** Live storm tracks and forecast cones, NEXRAD radar and satellite imagery, Forecast radar and satellite animation, Numerical forecast models (GFS, ECMWF), Real-time lightning detection, 3D hurricane and radar viewers (Pro)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic Monthly | $4.99 | per month |
| Pro Monthly | $9.99 | per month |
| Basic Annual | $50.90 | per year |
| Pro Annual | $99.99 | per year |


## Frequently asked questions

### Is 51知灾害 free?

51知灾害 is free to download, with no in-app purchases.

### Is VortexWeather free?

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

### Do 51知灾害 or VortexWeather have ads?

VortexWeather shows ads; 51知灾害 does not.

### Which is updated more often, 51知灾害 or VortexWeather?

51知灾害 ships an update every 4 months, and VortexWeather fortnightly. Most recently, 51知灾害 was updated on November 3, 2026 and VortexWeather on November 6, 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.*