# OstSeeTiere vs GEOMAR Authenticator

The clearest difference is update cadence: GEOMAR Authenticator at every 3 months against OstSeeTiere's every 6 months. GEOMAR Authenticator also leads on iOS requirement (13.0 vs 18.6). On price, ads, in-app purchases and device support there is nothing between them.

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

OstSeeTiere ships an update every 6 months, GEOMAR Authenticator every 3 months. The most recent releases landed on June 24, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | OstSeeTiere | GEOMAR Authenticator |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 20.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 3 months** |
| Monetization | Free | — |
| Size | 2 MB | 42 MB |
| Requires iOS | 18.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Emden](https://appshunter.io/developer/761214887) | [NetKnights GmbH](https://appshunter.io/developer/1445401030) |

## What reviewers say

### OstSeeTiere

[App page](https://appshunter.io/ios/app/ostseetiere/id943239243)

Report sightings and strandings of Baltic Sea marine mammals, including porpoises and seals. All submitted data is publicly displayed on an interactive map and scientifically analyzed to aid conservation efforts and research.

**Highlights:** Report marine mammal sightings, Report marine mammal strandings, Interactive map of sightings, Scientific data analysis, Supports conservation efforts, Information on porpoises and seals

**Features:** macOS Compatibility

**In-app purchases:** none


### GEOMAR Authenticator

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

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

**In-app purchases:** none


## Frequently asked questions

### Is OstSeeTiere free?

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

### Is GEOMAR Authenticator free?

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

### Do OstSeeTiere or GEOMAR Authenticator have ads?

Neither OstSeeTiere nor GEOMAR Authenticator shows ads.

### Which is updated more often, OstSeeTiere or GEOMAR Authenticator?

OstSeeTiere ships an update every 6 months, and GEOMAR Authenticator every 3 months. Most recently, OstSeeTiere was updated on June 24, 2026 and GEOMAR Authenticator on September 9, 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.*