Comparison

EF Scale vs Cyanometer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

EF Scale

Assess tornado and wind damage with this tool that simplifies the Enhanced Fujita (EF) Scale. Follow on-screen prompts to select damage indicators and degrees of damage, then adjust for construction variability to estimate wind speeds.

Highlights
  • Simplified EF Scale assessment
  • Damage indicator selection
  • Degree of damage input
  • Construction variability adjustment
  • Visual damage examples
  • About and share functions
Features
Read full description

Rate tornado damage the way surveyors do. EF Scale puts the complete Enhanced Fujita scale on your iPhone, iPad, and Mac — all 28 damage indicators, every degree of damage, and the expected wind speeds behind each rating. Browse structure types from small barns and family residences to high-rise buildings, transmission lines, and trees. Compare what you see against reference photos and construction details, then pick a degree of damage and tune the wind speed estimate between its bounds to account for construction quality. • All 28 damage indicators of the Enhanced Fujita scale • Reference photos and construction details for every indicator • Degrees of damage with expected wind speeds and EF ratings • Interactive wind speed estimator with adjustable bounds • EF0–EF5 rating reference, always a tap away • Everything stored on device — works fully offline in the field Built for storm spotters, damage surveyors, emergency managers, students, and weather enthusiasts. *** PLEASE REMEMBER: This app is for reference purposes only. Doing a real damage survey takes knowledge and experience you can't build into an app! Official damage assessments are the business of the National Weather Service and their delegates! ***

About

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.

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
Currently charting
Read 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.

Screenshots

EF Scale4 screens
Cyanometer4 screens

Verdict

The call

The clearest difference is price: EF Scale at Free against Cyanometer's $0.99. EF Scale also leads on rating (4.5 vs 2.8) and review sentiment (67% vs 25%). Cyanometer's advantage is chart position (#189 vs unranked) and iOS requirement (16 vs 26.0). On ratings volume, update cadence, ads and in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

EF Scale is free to download; Cyanometer costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

EF Scale holds the better App Store score, 4.5 against 2.8. Both are backed by a comparable volume of ratings — 4 and 4 respectively. Written reviews point the same way: 67% of EF Scale's written reviews are positive against 25% of Cyanometer's.

UpkeepUpdate frequency

EF Scale ships an update every 20 months, Cyanometer every 39 months. The most recent releases landed on August 8, 2026 and September 22, 2026 respectively.

Scorecard6 real differences · 5 level
EF Scale versus Cyanometer: the parameters behind the verdict, then further details
ParameterEF ScaleCyanometer
PriceFree — better$0.99
Rating4.5 (4 ratings) — better2.8 (4 ratings)
Positive reviews66.7% of reviews — better25.0% of reviews
Number of ratings44
Update frequencyEvery 20 months — betterEvery 39 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank—#189 — better
DevicesiPhone, iPad, Mac — betteriPhone, iPod
Requires iOS26.016 — better
Further details — not scored
Size18 MB14 MB
Age rating4+4+
DeveloperWeatherWary LLCJan-Hendrik von Kuick

Customer experience

EF Scale

All ratings4 ratings
Positive75.0%
Neutral25.0%
Negative0.0%
Written reviews9 reviews
Positive66.7%
Neutral22.2%
Negative11.1%

Cyanometer

All ratings4 ratings
Positive25.0%
Neutral25.0%
Negative50.0%
Written reviews4 reviews
Positive25.0%
Neutral0.0%
Negative75.0%

In-app purchases

None

EF Scale

No in-app purchases

None

Cyanometer

No in-app purchases

Questions

Is EF Scale free?
EF Scale is free to download, with no in-app purchases.
Is Cyanometer free?
Cyanometer costs $0.99, with no in-app purchases.
Which has better reviews, EF Scale or Cyanometer?
EF Scale is rated higher. EF Scale averages 4.5 out of 5 from 4 ratings, while Cyanometer averages 2.8 from 4 ratings.
Do EF Scale or Cyanometer have ads?
Neither EF Scale nor Cyanometer shows ads.
Which is updated more often, EF Scale or Cyanometer?
EF Scale ships an update every 20 months, and Cyanometer every 39 months. Most recently, EF Scale was updated on August 8, 2026 and Cyanometer on September 22, 2026.

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