Cyanometer vs Solar Activity Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Cyanometer
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.
- 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
Read full descriptionHide full description
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.
Solar Activity Pro
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.
- 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
Read full descriptionHide full description
Solar Activity Pro — your space weather companion Geomagnetic and solar activity can affect how you feel — from headaches and fatigue to general malaise — and can also influence technical systems such as GPS, satellites, and radio communications. Solar Activity Pro helps you stay informed about what is happening on the Sun and around Earth, whether you are an aurora hunter, a space weather enthusiast, or simply curious about solar storms. NEW: Aurora Map Explore Northern Lights probability on an interactive world map powered by NOAA OVATION data. Tap anywhere to see aurora probability, coordinates, and place name. Customize the map with multiple styles, cloud overlay, aurora intensity, and your current location. Stay informed - Push notifications for NOAA space weather alerts - Alerts screen with solar activity warnings and impacts timeline - Live dashboard with key gauges (solar wind speed, density, Bz, Bt, Kp, Dst, magnetometer, electron flux) - Boulder Kp index with trend direction Forecasts - Kp and Ap index forecasts - Predicted solar wind - 24-hour and weekly outlooks - Solar activity reports - Sunspot number and F10.7 radio flux forecasts Observations (last 24 hours) - Solar wind speed, density, and temperature - Magnetometer data - Electron and proton flux Aurora - Interactive Aurora Map (NOAA OVATION) - Northern and Southern Lights models - Tonight and tomorrow aurora outlook - Live aurora cameras Models & maps - Solar wind velocity, density, and pressure animations - Global and regional ionospheric perturbation maps - Total Electron Content (TEC) — global and North America - CTIPe, WAM-IPE, and GloTEC models Media - Aurora cameras from observation stations - Latest solar images (including DSCOVR) - Space weather videos Knowledge base - Phenomena — 16 illustrated topics: aurora, coronal holes, CMEs, geomagnetic storms, solar wind, flares, sunspots, ionosphere, radiation belts, cosmic rays, and more - Impacts — how space weather affects GPS, HF radio, satellites, power grids, and satellite drag Widgets Add live data to your Home Screen: - Planetary Kp index - Space weather conditions - DSCOVR solar view - Latest X-ray flare event - Observations - Aurora cameras - Solar images Access to the application is carried out through a subscription system. You can choose a subscription for one month or one year. Payment will be charged to iTunes Account at confirmation of purchase. Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period. Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal. Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase App used standard EULA agreement - https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ App privacy policy - https://drive.google.com/file/d/1ksHp-nv_gkoOiqq6i8wENw9LJw-ey8NH/view?usp=sharing
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Cyanometer | Solar Activity Pro |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 2.8 (4 ratings) | 4.2 (5 ratings) — better |
| Positive reviews | 25.0% of reviews | 50.0% of reviews — better |
| Number of ratings | 4 | 5 — better |
| Update frequency | Every 39 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid — better | Subscription |
| Best chart rank | #198 — better | — |
| Devices | iPhone, iPod | iPhone, iPad, Mac — better |
| Requires iOS | 16 — better | 17 |
| Further details — not scored | ||
| Size | 14 MB | 40 MB |
| Age rating | 4+ | 4+ |
| Developer | Jan-Hendrik von Kuick | Pavel Koyushev |
Customer experience
Cyanometer
Solar Activity Pro
In-app purchases
Cyanometer
No in-app purchases
Solar Activity Pro
- Monthly subscription$2.991 Month
- 3 Months subscription$6.993 Months
- Yearly subscription$17.991 Year
Questions
Is Cyanometer free?
Is Solar Activity Pro free?
Which has better reviews, Cyanometer or Solar Activity Pro?
Do Cyanometer or Solar Activity Pro have ads?
Which is updated more often, Cyanometer or Solar Activity Pro?
Other comparisons















