# GEOMAR Authenticator vs ReefManager App

The clearest difference is in-app purchases: GEOMAR Authenticator at none against ReefManager App's 8. GEOMAR Authenticator also leads on iOS requirement (13.0 vs 15.0). ReefManager App's advantage is update cadence (every 3 days vs every 3 months). On price, ads and device support there is nothing between them.

Both are free to download. ReefManager App sells 8 in-app purchases, starting at $3.99 per month. GEOMAR Authenticator asks for nothing beyond the download.

GEOMAR Authenticator ships an update every 3 months, ReefManager App every 3 days. The most recent releases landed on September 9, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | GEOMAR Authenticator | ReefManager App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/reefmanager-app/id6746875163/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 95.2% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 days** |
| Monetization | — | Free with in-app purchases |
| Size | 42 MB | 269 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 9+ |
| Developer | [NetKnights GmbH](https://appshunter.io/developer/1445401030) | [CHRISTIAN KITZEL](https://appshunter.io/developer/1818875291) |

## What reviewers say

### GEOMAR Authenticator

[App page](https://appshunter.io/ios/app/geomar-authenticator/id6476554059)

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

**In-app purchases:** none


### ReefManager App

[App page](https://appshunter.io/ios/app/reefmanager-app/id6746875163)

This app offers a scientifically-backed approach to maintaining a stable and healthy reef aquarium. It uses intelligent algorithms and personalized AI to analyze your data, providing precise recommendations for water parameters and trace elements, replacing guesswork with data-driven insights.

**Highlights:** Intelligent water parameter stabilization, Precise ICP analysis and trace element calculation, Personalized AI assistant for tailored advice, Comprehensive scientific knowledge database, Interactive community map for connecting with others

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| AI - 1 month | $3.99 | per month |
| ICP - 1 year | $3.99 | per month |
| Measurement - 1 month | $4.99 | per month |
| Full-Mode Abo - 1 month | $8.99 | per month |
| AI - 1 month | $29.99 | per year |
| ICP - 1 year | $39.99 | per year |
| Messungen - 1 Jahr | $39.99 | per year |
| Full-Mode - 1 year | $69.99 | per year |


## Frequently asked questions

### Is GEOMAR Authenticator free?

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

### Is ReefManager App free?

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

### Do GEOMAR Authenticator or ReefManager App have ads?

Neither GEOMAR Authenticator nor ReefManager App shows ads.

### Which is updated more often, GEOMAR Authenticator or ReefManager App?

GEOMAR Authenticator ships an update every 3 months, and ReefManager App every 3 days. Most recently, GEOMAR Authenticator was updated on September 9, 2026 and ReefManager App on September 22, 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.*