Wind Reader vs Calypso Ballistics
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Wind Reader
This application calculates real-time wind speed for long-range shooting using the Eagleman Technique. It leverages your phone's inclination sensor to convert mirage and rain angles into accurate wind speed measurements, a method patented in the US.
- Real-time wind speed calculation
- Eagleman Technique implementation
- Uses phone inclination sensor
- Converts mirage and rain angles
- Patented wind reading method
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Wind reading for long range shooting. This app uses the Eagleman Technique. The phone's inclination sensor is used to convert mirage and rain angles to wind speed. The Eagleman Technique was developed by James Eagleman in 1992 to provide real-time wind speed based on mirage/rain angles and percentages. The method has a US Patent. James Eagleman is the master instructor for the Barbour Creek Long Range School (http://barbourcreek.com).
Calypso Ballistics
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Calypso Ballistics turns your Calypso ultrasonic anemometer into a wind instrument for precision shooting: it measures the real wind at your position and breaks it down against your line of fire, ready to take to your ballistic calculator. THE WIND, FROM THE LINE OF FIRE Set the anemometer pointing downrange. The app splits the wind into its crosswind component — with the side it comes from — and its head or tail component, and gives you the wind value and the clock hour it blows from. SHOOTER'S CLOCK AND MAGNETIC ROSE A dial with the shooter's clock — 12 o'clock is the line of fire — inside a magnetic rose turned to your bearing to target. At a glance: which hour the wind is from, what that wind is worth, and how strong. LULL, NOW AND GUST The crosswind bracket over a window you choose, so you see the band the wind moves in instead of chasing the instant reading. AIR DENSITY AND DENSITY ALTITUDE With a WeatherDot paired, or with temperature, pressure and humidity entered by hand, it computes humid-air density and density altitude, with the whole calculation in view. It tells station pressure from barometric, the mistake that hurts a ballistic solution most. NO BLACK BOXES Every formula the app uses is explained inside it. LOGBOOK AND CHARTS Every connection is recorded as a session, with wind, direction, temperature, pressure and humidity. Live charts and CSV export. Data stays on your device. ALSO · Three modes: simple, standard and pro · Long-press configurable readouts · Guide to placing the anemometer pointing at the target · Demo mode to try the app without a sensor · Configurable wind, temperature and pressure units · Screen kept awake while in use · English and Spanish Calypso Ballistics does not compute trajectories or firing corrections: it measures the wind and the atmosphere so your ballistic calculator works with real data. It is a measurement instrument for sport shooting. Requires a Calypso Instruments Bluetooth anemometer. The WeatherDot is optional.
Screenshots
Verdict
Wind Reader and Calypso Ballistics are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Wind Reader ships an update weekly, Calypso Ballistics every 5 days. The most recent releases landed on September 23, 2026 and October 25, 2026 respectively.
| Parameter | Wind Reader | Calypso Ballistics |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (5 ratings) — better | — |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 5 — better | — |
| Update frequency | Weekly | Every 5 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 15.0 | 15.0 |
| Further details — not scored | ||
| Size | 2 MB | 20 MB |
| Age rating | 17+ | 4+ |
| Developer | James Eagleman | Calypso Instruments |
In-app purchases
Wind Reader
No in-app purchases
Calypso Ballistics
No in-app purchases
Questions
Is Wind Reader free?
Is Calypso Ballistics free?
Do Wind Reader or Calypso Ballistics have ads?
Which is updated more often, Wind Reader or Calypso Ballistics?
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