# EyeOnWater vs Nature's Notebook

The clearest difference is rating: Nature's Notebook at 3.2 against EyeOnWater's 2.5. Nature's Notebook also leads on update cadence (every 3 weeks vs every 2 months) and ratings volume (27 vs 2). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Nature's Notebook holds the better App Store score, 3.2 against 2.5. That said, the two scores are not equally well evidenced: Nature's Notebook has 27 ratings behind it against 2, so its average is the more settled of the two.

EyeOnWater ships an update every 2 months, Nature's Notebook every 3 weeks. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | EyeOnWater | Nature's Notebook |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.5 (2 ratings)](https://appshunter.io/ios/app/eyeonwater-colour/id1021542366/reviews) | **[3.2 (27 ratings)](https://appshunter.io/ios/app/natures-notebook/id1463430668/reviews)** |
| Number of ratings | 2 | **27** |
| Positive reviews | — | 40.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 31 MB | 47 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MARIS B.V.](https://appshunter.io/developer/964066073) | [National Phenology Network](https://appshunter.io/developer/843843359) |

## What reviewers say

### EyeOnWater

[App page](https://appshunter.io/ios/app/eyeonwater-colour/id1021542366)

Contribute to scientific research by measuring and reporting the color of nearby bodies of water. Your data helps scientists track water quality and life within it over time, building on a long-standing scientific observation method.

**Highlights:** Measure water color, Contribute to scientific research, Track water quality, Observe algae presence, Utilize Forel-Ule scale, View data on website

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

**In-app purchases:** none


### Nature's Notebook

[App page](https://appshunter.io/ios/app/natures-notebook/id1463430668)

Record observations of plant and animal life cycles, such as flowering and migration. Mark observation sites, create species lists, and log seasonal changes in nature.

**Highlights:** Record plant and animal life cycle events, Mark observation sites, Create species lists, Log seasonal observations, Citizen science program

**In-app purchases:** none


## Frequently asked questions

### Is EyeOnWater free?

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

### Is Nature's Notebook free?

Nature's Notebook is free to download, with no in-app purchases.

### Which has better reviews, EyeOnWater or Nature's Notebook?

Nature's Notebook is rated higher. EyeOnWater averages 2.5 out of 5 from 2 ratings, while Nature's Notebook averages 3.2 from 27 ratings.

### Do EyeOnWater or Nature's Notebook have ads?

Neither EyeOnWater nor Nature's Notebook shows ads.

### Which is updated more often, EyeOnWater or Nature's Notebook?

EyeOnWater ships an update every 2 months, and Nature's Notebook every 3 weeks. Most recently, EyeOnWater was updated on November 1, 2026 and Nature's Notebook on November 3, 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.*