Theta vs Light Spectrometer Wavelength
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Theta
This application connects to specialized devices to measure and display galvanic skin response. It utilizes Wi-Fi and Bluetooth 4.0BLE to collect data on skin conductance, providing insights into physiological responses.
- Galvanic skin response measurement
- Wi-Fi connectivity
- Bluetooth 4.0BLE connection
- Skin conductance data display
- Physiological response tracking
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Application displays data from Theta-Meter devices (Wi-Fi and Bluetooth 4.0BLE connection) which measures human body galvanic skin response. Skin conductance, also known as galvanic skin response (GSR), electrodermal response (EDR), psychogalvanic reflex (PGR), skin conductance response (SCR) or skin conductance level (SCL), is a method of measuring the electrical conductance of the skin.
Light Spectrometer Wavelength
This application analyzes light to determine its dominant wavelength in nanometers, frequency in terahertz, and period length in femtoseconds. It provides real-time measurements and allows users to save their findings with notes. The app is designed for measuring colored light sources.
- Measures dominant wavelength (nm)
- Measures frequency (THz)
- Measures period length (fs)
- Real-time measurement
- Save measurements with notes
- Optional calibration
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Measures light spectrum to determine the dominant wavelength in nm, frequency in THz and period length in fs. DOMINANT WAVELENGTH Dominant wavelength is a concept commonly used in the field of color science and perception. It refers to the wavelength of light that appears most prominent or dominant in a given color mixture or light source. In other words, it is the wavelength that our eyes perceive as the primary color in a mixture of different wavelengths. For light with only one wavelength, such as the light from a colored LED, the dominant wavelength corresponds to the wavelength of that light. KEY FEATURES • High accuracy • Real-time measurement • Measures light wavelength in nanometers (nm) • Measures light frequency in terahertz (Thz) • Measures light period length in femtoseconds (fs) • Easy to use • Save measurements with notes • Supports 40 languages, including english • Optional calibration for enhanced precision MEASURING 1. Find a white surface, such as a plain piece of white paper 2. Point your camera at the surface illuminated by your target light source 3. The app gives you accurate measurements in real-time LIMITATIONS Smartphone cameras have limitations when it comes to distinguishing between different very short, or very long wavelengths. More specifically, on many devices the accuracy below 465 nm and above 610 nm is very limited. This is due to the physical camera sensors in the devices. An automatic warning appears on the screen for these short and long wavelengths. WHITE LIGHT Note that is not meaningful to measure the dominant wavelength of white light as white light consists of a wide range of wavelengths, with no wavelength dominating. This app is made for measuring colored light. If you are interested in determining the color temperature of white light, please instead use our popular White Balance Kelvin Meter app. COLOR OF SURFACES If you want to measure the color of a surface or material, rather than of light, please instead use our popular Colorimeter Camera Color Meter app. Privacy Policy, https://spectrometer.contechity.com/pp.html End User License Agreement, https://spectrometer.contechity.com/eula.html CONTACT I value your feedback. Email me at apps@contechity.com with any suggestions or questions. Download the Spectrometer now!
Screenshots
Verdict
The clearest difference is rating: Theta at 5.0 against Light Spectrometer Wavelength's 4.2. Theta also leads on in-app purchases (none vs 7) and review sentiment (100% vs 71%). Light Spectrometer Wavelength's advantage is ratings volume (96 vs 1). On price, update cadence, ads and device support 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
Both are free to download. Light Spectrometer Wavelength sells 4 in-app purchases, starting at $0.99 per month. Theta asks for nothing beyond the download.
Theta holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: Light Spectrometer Wavelength has 96 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Theta's written reviews are positive against 71% of Light Spectrometer Wavelength's.
Theta ships an update monthly, Light Spectrometer Wavelength every 2 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.
| Parameter | Theta | Light Spectrometer Wavelength |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.2 (96 ratings) |
| Positive reviews | 100.0% of reviews — better | 70.6% of reviews |
| Number of ratings | 1 | 96 — better |
| Update frequency | Monthly — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 13 MB | 43 MB |
| Age rating | 12+ | 4+ |
| Developer | Mikhail Fedorov | Contechity AB |
Customer experience
Theta
Light Spectrometer Wavelength
In-app purchases
Theta
No in-app purchases
Light Spectrometer Wavelength
- Full Access7 Days trial$0.991 Month
- Full access14 Days trial$0.991 Month
- Full access$4.991 Year
- Full access4 variants$6.99
Questions
Is Theta free?
Is Light Spectrometer Wavelength free?
Which has better reviews, Theta or Light Spectrometer Wavelength?
Do Theta or Light Spectrometer Wavelength have ads?
Which is updated more often, Theta or Light Spectrometer Wavelength?
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