# Jellywatch vs W2O

The clearest difference is update cadence: Jellywatch at every 3 months against W2O's every 24 months. W2O's advantage is review sentiment (100% vs 91%) and ratings volume (3 vs 1). On price, rating, ads and in-app purchases there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for Jellywatch against 5.0 for W2O. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews are what separate them: 91% of Jellywatch's written reviews are positive against 100% of W2O's.

Jellywatch ships an update every 3 months, W2O every 24 months. The most recent releases landed on October 5, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Jellywatch | W2O |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/jellywatch/id545501733/reviews) | [5.0 (3 ratings)](https://appshunter.io/ios/app/w2o/id1556719456/reviews) |
| Number of ratings | 1 | **3** |
| Positive reviews | 90.9% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 24 months |
| Monetization | Free | Free |
| Size | 6 MB | 8 MB |
| Requires iOS | **14.0** | 14.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Monterey Bay Aquarium Research Institute](https://appshunter.io/developer/997448509) | [Bjorn Grigholm](https://appshunter.io/developer/1556719458) |

## What reviewers say

### Jellywatch

[App page](https://appshunter.io/ios/app/jellywatch/id545501733)

This app serves as a global database for monitoring ocean conditions, focusing on jellyfish populations. It empowers citizen scientists to submit observations and photos, contributing to freely accessible data on blooms, red tides, and general marine environments. Species identification is also offered for submitted images.

**Highlights:** Ocean condition monitoring, Jellyfish population tracking, Citizen science reporting, Global data submission, Species identification, Free data access

**Features:** macOS Compatibility

**In-app purchases:** none


### W2O

[App page](https://appshunter.io/ios/app/w2o/id1556719456)

Access a wealth of ocean-related content, including weekly radio episodes, blog posts on policy and action, and a digital magazine exploring ocean culture and solutions. Stay informed about initiatives and join a global community dedicated to ocean health and sustainability.

**Highlights:** Weekly radio episodes on ocean issues, Blog on ocean policy and action, Digital magazine on ocean culture, Monthly newsletter updates, Global community for ocean conservation

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Jellywatch free?

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

### Is W2O free?

W2O is free to download, with no in-app purchases.

### Which has better reviews, Jellywatch or W2O?

Jellywatch and W2O are both rated 5.0 out of 5 on the App Store, from 1 and 3 ratings respectively.

### Do Jellywatch or W2O have ads?

Neither Jellywatch nor W2O shows ads.

### Which is updated more often, Jellywatch or W2O?

Jellywatch ships an update every 3 months, and W2O every 24 months. Most recently, Jellywatch was updated on October 5, 2026 and W2O on September 20, 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.*