# FDR Calculator vs WindNinja Mobile

The clearest difference is in-app purchases: WindNinja Mobile at none against FDR Calculator's 1. WindNinja Mobile also leads on review sentiment (33% vs 0%) and iOS requirement (13.0 vs 15.0). FDR Calculator's advantage is update cadence (every 4 months vs every 8 months). On price, ads and device support there is nothing between them.

Both are free to download. FDR Calculator sells 1 in-app purchase, starting at $1.99 per month. WindNinja Mobile asks for nothing beyond the download.

FDR Calculator ships an update every 4 months, WindNinja Mobile every 8 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | FDR Calculator | WindNinja Mobile |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[2.6 (9 ratings)](https://appshunter.io/ios/app/windninja-mobile/id1086703676/reviews)** |
| Number of ratings | — | **9** |
| Positive reviews | 0.0% of reviews | **33.3% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 8 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 35 MB | 108 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Alan Richert](https://appshunter.io/developer/527055673) | [US Forest Service](https://appshunter.io/developer/949583790) |

## What reviewers say

### FDR Calculator

[App page](https://appshunter.io/ios/app/fdr-calculator/id527055670)

Instantly calculate fire danger ratings with professional-grade algorithms. Offers real-time weather data integration, visual danger level displays, and detailed action recommendations for informed fire prevention and management.

**Highlights:** Instant Fire Danger Index calculations, Real-time weather data integration, Visual color-coded danger levels, Detailed action recommendations, Manual calculator for offline use, Automatic location detection

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weather Pro (Monthly) | $1.99 | per month |


### WindNinja Mobile

[App page](https://appshunter.io/ios/app/windninja-mobile/id1086703676)

This mobile application provides a user interface for initiating and viewing wind field simulations. It is designed to support wildland fire management by computing spatially varying wind data. More information is available on the firelab.org website.

**Highlights:** Initiate wind simulations, View wind field data, Spatially varying wind computation, Wildland fire support tool, Mobile interface

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

**In-app purchases:** none


## Frequently asked questions

### Is FDR Calculator free?

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

### Is WindNinja Mobile free?

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

### Do FDR Calculator or WindNinja Mobile have ads?

Neither FDR Calculator nor WindNinja Mobile shows ads.

### Which is updated more often, FDR Calculator or WindNinja Mobile?

FDR Calculator ships an update every 4 months, and WindNinja Mobile every 8 months. Most recently, FDR Calculator was updated on November 1, 2026 and WindNinja Mobile on November 2, 2026.

---

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