# Cyanometer vs Solar Activity Pro

The clearest difference is price: Solar Activity Pro at Free against Cyanometer's $0.99. Solar Activity Pro also leads on rating (4.2 vs 2.8) and update cadence (fortnightly vs every 39 months). Cyanometer's advantage is in-app purchases (none vs 3) and chart position (#198 vs unranked). On ratings volume, ads, device support and iOS requirement there is nothing between them.

Solar Activity Pro is free to download; Cyanometer costs $0.99 up front. Solar Activity Pro sells 3 in-app purchases, starting at $2.99 per month. Cyanometer asks for nothing beyond the download.

Solar Activity Pro holds the better App Store score, 4.2 against 2.8. Both are backed by a comparable volume of ratings — 4 and 5 respectively. Written reviews point the same way: 25% of Cyanometer's written reviews are positive against 50% of Solar Activity Pro's.

Cyanometer ships an update every 39 months, Solar Activity Pro fortnightly. The most recent releases landed on September 22, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Cyanometer | Solar Activity Pro |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [2.8 (4 ratings)](https://appshunter.io/ios/app/cyanometer/id1476812898/reviews) | **[4.2 (5 ratings)](https://appshunter.io/ios/app/solar-activity-pro/id1545198636/reviews)** |
| Number of ratings | 4 | **5** |
| Positive reviews | 25.0% of reviews | **50.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 39 months | **Fortnightly** |
| Monetization | **Paid** | Subscription |
| Best chart rank | **#198** | — |
| Size | 14 MB | 40 MB |
| Requires iOS | **16** | 17 |
| Devices | iPhone, iPod | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Jan-Hendrik von Kuick](https://appshunter.io/developer/1190145903) | [Pavel Koyushev](https://appshunter.io/developer/1257728721) |

## What reviewers say

### Cyanometer

[App page](https://appshunter.io/ios/app/cyanometer/id1476812898)

**Currently charting:** #198 Top Paid · Weather (US App Store)

Measure the intensity of blue in the sky to understand atmospheric conditions. Save scans with location and time data for comparison across different places. Offers modern, historical, and custom color scales.

**Highlights:** 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

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

**In-app purchases:** none


### Solar Activity Pro

[App page](https://appshunter.io/ios/app/solar-activity-pro/id1545198636)

Monitor solar activity and its potential effects on well-being and technology. Get aurora forecasts, real-time data, and customizable widgets. Stay informed about space weather events with detailed indicators and notifications.

**Highlights:** Widgets for solar activity, Push notifications, Aurora forecast and cameras, KP and AP index tracking, Solar wind and electron/proton flux data, Sunspot and electron content maps

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly subscription | $2.99 | per month |
| 3 Months subscription | $6.99 | per 3 months |
| Yearly subscription | $17.99 | per year |


## Frequently asked questions

### Is Cyanometer free?

Cyanometer costs $0.99, with no in-app purchases.

### Is Solar Activity Pro free?

Solar Activity Pro is free to download, with in-app purchases available.

### Which has better reviews, Cyanometer or Solar Activity Pro?

Solar Activity Pro is rated higher. Cyanometer averages 2.8 out of 5 from 4 ratings, while Solar Activity Pro averages 4.2 from 5 ratings.

### Do Cyanometer or Solar Activity Pro have ads?

Neither Cyanometer nor Solar Activity Pro shows ads.

### Which is updated more often, Cyanometer or Solar Activity Pro?

Cyanometer ships an update every 39 months, and Solar Activity Pro fortnightly. Most recently, Cyanometer was updated on September 22, 2026 and Solar Activity Pro 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.*