# Cotton Gin Air Calculator vs Authenticator

The clearest difference is in-app purchases: Cotton Gin Air Calculator at none against Authenticator's 2. Cotton Gin Air Calculator also leads on iOS requirement (10.0 vs 18.5). Authenticator's advantage is update cadence (weekly vs every 22 months). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. Authenticator sells 2 in-app purchases, starting at $9.99 per 7 days. Cotton Gin Air Calculator asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for Cotton Gin Air Calculator against 5.0 for Authenticator. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

Cotton Gin Air Calculator ships an update every 22 months, Authenticator weekly. The most recent releases landed on October 21, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Cotton Gin Air Calculator | Authenticator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/cotton-gin-air-calculator/id1161028948/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/authenticator-2fa-app/id6760155508/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 22 months | **Weekly** |
| Monetization | **Free** | Subscription |
| Size | 13 MB | 112 MB |
| Requires iOS | **10.0** | 18.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [MARTIN Mehner](https://appshunter.io/developer/1155932304) | [BU Guard GmbH](https://appshunter.io/developer/1858539616) |

## What reviewers say

### Cotton Gin Air Calculator

[App page](https://appshunter.io/ios/app/cotton-gin-air-calculator/id1161028948)

This utility app calculates air velocity and volume in ducts using pitot tube readings. It's designed for industrial applications, assuming standard air conditions. Measurements are taken in inches of water column and duct diameter.

**Highlights:** Air velocity calculation, Air volume calculation, Pitot tube velocity pressure input, Supports inches water column, Supports round duct diameter in inches, Assumes standard air conditions

**Features:** macOS Compatibility

**In-app purchases:** none


### Authenticator

[App page](https://appshunter.io/ios/app/authenticator-2fa-app/id6760155508)

Consolidate your digital security with this comprehensive platform. It offers two-factor authentication codes, password management, an encrypted vault for sensitive files, and a private browser with autofill capabilities, all protected by end-to-end encryption and Face ID.

**Highlights:** 2FA Authentication (TOTP/HOTP), Password Manager, Secure Vault for files, Private Browser, Auto Fill for codes and passwords, Cloud Sync for backups, Widgets for quick access

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Access | $9.99 | per 7 days |
| Premium Access Year | $44.99 | per year |


## Frequently asked questions

### Is Cotton Gin Air Calculator free?

Cotton Gin Air Calculator is free to download, with no in-app purchases.

### Is Authenticator free?

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

### Which has better reviews, Cotton Gin Air Calculator or Authenticator?

Cotton Gin Air Calculator and Authenticator are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.

### Do Cotton Gin Air Calculator or Authenticator have ads?

Neither Cotton Gin Air Calculator nor Authenticator shows ads.

### Which is updated more often, Cotton Gin Air Calculator or Authenticator?

Cotton Gin Air Calculator ships an update every 22 months, and Authenticator weekly. Most recently, Cotton Gin Air Calculator was updated on October 21, 2026 and Authenticator on October 25, 2026.

---

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