Comparison

eDPPT vs Light Spectrometer Wavelength

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

Head to head
About

eDPPT

Features
Read full description

Introducing the eDPPT companion app for iOS! Stay connected to the eDPPT digital paging system for emergency responders like never before. Our app provides seamless pager connectivity via Bluetooth, delivering critical messages straight to your device.

About

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.

Highlights
  • Measures dominant wavelength (nm)
  • Measures frequency (THz)
  • Measures period length (fs)
  • Real-time measurement
  • Save measurements with notes
  • Optional calibration
Features
Read full description

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

eDPPT4 screens
Light Spectrometer Wavelength4 screens

Verdict

The call

The clearest difference is in-app purchases: eDPPT at none against Light Spectrometer Wavelength's 7. eDPPT also leads on iOS requirement (13.0 vs 15.0). Light Spectrometer Wavelength's advantage is update cadence (every 2 months vs every 39 months). On price, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Light Spectrometer Wavelength sells 4 in-app purchases, starting at $0.99 per month. eDPPT asks for nothing beyond the download.

UpkeepUpdate frequency

eDPPT ships an update every 39 months, Light Spectrometer Wavelength every 2 months. The most recent releases landed on October 19, 2026 and October 24, 2026 respectively.

Scorecard3 real differences · 7 level
eDPPT versus Light Spectrometer Wavelength: the parameters behind the verdict, then further details
ParametereDPPTLight Spectrometer Wavelength
PriceFreeFree
Rating—4.2 (96 ratings) — better
Positive reviews—72.7% of reviews
Number of ratings—96 — better
Update frequencyEvery 39 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS13.0 — better15.0
Further details — not scored
Size8 MB43 MB
Age rating4+4+
DeveloperDavid DieffenderferContechity AB

In-app purchases

None

eDPPT

No in-app purchases

4 purchases

Light Spectrometer Wavelength

Subscriptions3
  • Full Access7 Days trial$0.991 Month
  • Full access14 Days trial$0.991 Month
  • Full access$4.991 Year
One-time1
  • Full access4 variants$6.99

Questions

Is eDPPT free?
eDPPT is free to download, with no in-app purchases.
Is Light Spectrometer Wavelength free?
Light Spectrometer Wavelength is free to download, with in-app purchases available.
Do eDPPT or Light Spectrometer Wavelength have ads?
Neither eDPPT nor Light Spectrometer Wavelength shows ads.
Which is updated more often, eDPPT or Light Spectrometer Wavelength?
eDPPT ships an update every 39 months, and Light Spectrometer Wavelength every 2 months. Most recently, eDPPT was updated on October 19, 2026 and Light Spectrometer Wavelength on October 24, 2026.

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