# Wind Reader vs Calypso Ballistics

Wind Reader and Calypso Ballistics are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

Wind Reader ships an update weekly, Calypso Ballistics every 5 days. The most recent releases landed on September 23, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Wind Reader | Calypso Ballistics |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (5 ratings)](https://appshunter.io/ios/app/wind-reader/id6469385660/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | **Every 5 days** |
| Monetization | Free | — |
| Size | 2 MB | 20 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [James Eagleman](https://appshunter.io/developer/1464839727) | [Calypso Instruments](https://appshunter.io/developer/928168289) |

## What reviewers say

### Wind Reader

[App page](https://appshunter.io/ios/app/wind-reader/id6469385660)

This application calculates real-time wind speed for long-range shooting using the Eagleman Technique. It leverages your phone's inclination sensor to convert mirage and rain angles into accurate wind speed measurements, a method patented in the US.

**Highlights:** Real-time wind speed calculation, Eagleman Technique implementation, Uses phone inclination sensor, Converts mirage and rain angles, Patented wind reading method

**Features:** macOS Compatibility

**In-app purchases:** none


### Calypso Ballistics

[App page](https://appshunter.io/ios/app/calypso-ballistics/id6815266601)

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

**In-app purchases:** none


## Frequently asked questions

### Is Wind Reader free?

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

### Is Calypso Ballistics free?

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

### Do Wind Reader or Calypso Ballistics have ads?

Neither Wind Reader nor Calypso Ballistics shows ads.

### Which is updated more often, Wind Reader or Calypso Ballistics?

Wind Reader ships an update weekly, and Calypso Ballistics every 5 days. Most recently, Wind Reader was updated on September 23, 2026 and Calypso Ballistics on October 25, 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.*