# Cyanometer — Himmelblau messen

> Instrument for measuring sky blueness and atmospheric conditions. (iPhone/iPad app by Jan-Hendrik von Kuick.)

- Source: https://appshunter.io/ios/app/cyanometer/id1476812898 (this page in markdown: same URL + `.md`)
- Developer: [Jan-Hendrik von Kuick](https://appshunter.io/developer/1190145903)
- Category: Weather, Education
- Price: $0.99
- Rating: 2.80/5 from 4 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 16 · 14 MB
- Languages: American English, German (Germany)
- Released: 2019-08-29
- Data updated: 2026-09-07
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/cyanometer/id1476812898/reviews.md

## What is Cyanometer?

The original cyanometer was invented by the Genevan physicist and Alpine explorer Horace-Bénédict de Saussure (* 17 February 1740 in Conches; † 22 January 1799) in 1789. It is an instrument for measuring 'blueness', specifically the colour intensity of blue sky. With the measurement it is possible to draw conclusions from the constitution of the atmosphere: the bluer the sky the less the water vapor. Saussures cyanometer consisted out of 53 parts of a circular ring ranging from white over different grades of blue to black (Saussure used Prussian blue). Saussure used his cyanometer for measurements in Geneva, Chamonix und on the Mont Blanc.
Alexander von Humboldt used a cyanometer on his expedition to America (1799 - 1804).

You can use our Cyanometer in three modes: The modern scale uses distinct grades of blue starting with clear white up to black. The Saussure scale shall give an idea about the colors from Saussures original cyanometer. With the user defined scale own scans of blue skies can be added to an own colored circular ring - an own cyanometer.
Each scan is saved inside the app containing information about date, time and locality. So it is possible to compare scans of blue skies from different locations.

Privacy notice: No data will be saved or processed outside the app.

## Key features

- Measure sky blueness intensity
- Modern, Saussure, and custom scales
- Save scans with date, time, and location
- Compare sky conditions across locations
- Privacy-focused, no external data processing

## Chart rankings

- #72 in Top Paid · Weather (US App Store)

## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/cyanometer/id1476812898/reviews.md

### 1/5 — Does not even open

*2024-08-17*

How do I get a refund? I downloaded the app. Gave permission to use my location and camera but it doesn’t even open.

**Developer response:** We‘re very sorry, hearing, that our Cyanometer app doesn‘t start. Could you provide us with some further technical details like iOS version and what iPhone you‘re using? Thank you!

You can get a refund directly via Apples AppStore.

### 2/5 — It's just a dfferent way to access the camera.

*2023-02-21*

I had hoped and assumed that the app would use the blue in the image area and automatically suggest a number matching what shade of blue was visible. It does not.

The user picks a number on the round scale then presses the shutter button, saving some basic info and your selected blue number with the image.

Not sure there's a wide audience for this.

**Developer response:** Thank you for your review.
The app does what Horace Bénédict de Saussure did with his original Cyanometer. There was no automation -  he had to turn the device and to decide, which blue fits. We tried to give the user exactly that kind of ancient experience.
Nevertheless we‘ll take your idea as an improvement for the next version.

### 1/5 — rubbish

*2022-09-21*

Does not open on iOS…
I’m on iPhone 12 mini ios 14.5.1 and iPad 14.7.1
The app opens and failed immediately

**Developer response:** We‘re very sorry, hearing, that our Cyanometer app doesn‘t start. Could you provide us with some further technical details like iOS version and what iPhone you‘re using? Thank you!

### 5/5 — My sky, your sky

*2020-04-26*

I love this app.
Since reading about Humboldt’s Cyanometer in “The Invention of Nature” I’ve been a bit obsessed with the idea of measuring the blueness of the sky. I understand the blueness can be a measure of water content, but there is something also poetic and uniting about the cyanometer: we all share the same sky, yet it is for each of us a different sky. 
Use this app and your sky will never be simply blue again.

## Frequently asked questions about Cyanometer

### What is Cyanometer used for?

Cyanometer is an instrument for measuring the intensity of blue in the sky. This measurement can help draw conclusions about the constitution of the atmosphere, as a bluer sky generally indicates less water vapor.

### What are the different modes in Cyanometer?

Cyanometer offers three modes: a modern scale with distinct blue grades, the Saussure scale based on the original instrument, and a user-defined scale where you can add your own scanned blue skies.

### Can I save my sky measurements with Cyanometer?

Yes, each scan is saved within the app, including information about the date, time, and locality. This allows for easy comparison of sky conditions from different locations.

### Is Cyanometer available on multiple devices?

Based on the provided information, Cyanometer is supported on iPhone and iPod devices. It is not specified if it is available for Android or other platforms.

### How often is Cyanometer updated?

The latest version of Cyanometer is 2.0, which was last updated on January 16, 2026. This indicates a very recent update, suggesting active development.

### What is the price of Cyanometer?

Cyanometer is a paid application, priced at $0.99. There are no in-app purchases or subscriptions mentioned.

### Does Cyanometer have ads?

No, Cyanometer does not contain advertisements. The app is a paid download and is ad-free.

### What is the age rating for Cyanometer?

Cyanometer has an age rating of 4+, making it suitable for a wide range of users, including children and adults.

## Version history (last 3 releases)

### 2.0 — 2026-01-16

Complete refactoring:
- New scale display
- AI-assisted determination of the appropriate scale color
- Calculated humidity reading
- New menu navigation
- Scan images are saved within the app
- Results and images can be shared
- Scan data export function
- Comprehensive help documentation

### 1.1 — 2020-06-11

Fixes for iOS13/SDK 13.

### 1.0 — 2019-08-29

No release notes.

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## More apps by Jan-Hendrik von Kuick

- [Bleigiessen-Lexikon](https://appshunter.io/ios/app/bleigiessen-lexikon/id1190145904)
- [Leap Year Test](https://appshunter.io/ios/app/leap-year-test/id1371327368)
- [todsicher](https://appshunter.io/ios/app/todsicher/id1377333190)
- [ColorPicker Plus](https://appshunter.io/ios/app/colorpicker-plus/id1504275015)

All apps by Jan-Hendrik von Kuick: https://appshunter.io/developer/1190145903

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*