# Light Spectrometer Wavelength vs eRealSign Authenticator

The clearest difference is in-app purchases: eRealSign Authenticator at none against Light Spectrometer Wavelength's 7. On price, ads, device support and iOS requirement there is nothing between them.

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

## The numbers

| Metric | Light Spectrometer Wavelength | eRealSign Authenticator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.2 (94 ratings)](https://appshunter.io/ios/app/light-spectrometer-wavelength/id6450930820/reviews)** | — |
| Number of ratings | **94** | — |
| Positive reviews | 72.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | — |
| Monetization | Free with in-app purchases | — |
| Size | 43 MB | 49 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Contechity AB](https://appshunter.io/developer/1649290454) | [UAM TECHNOLOGIES CORP](https://appshunter.io/developer/1887657490) |

## What reviewers say

### Light Spectrometer Wavelength

[App page](https://appshunter.io/ios/app/light-spectrometer-wavelength/id6450930820)

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:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Access | $0.99 | per month |
| Full access | $0.99 | per month |
| Full access | $4.99 | per year |
| Full access | $6.99 | one-time |


### eRealSign Authenticator

[App page](https://appshunter.io/ios/app/erealsign-authenticator/id6761076971)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Light Spectrometer Wavelength free?

Light Spectrometer Wavelength is free to download, with in-app purchases available.

### Is eRealSign Authenticator free?

eRealSign Authenticator is free to download, with no in-app purchases.

### Do Light Spectrometer Wavelength or eRealSign Authenticator have ads?

Neither Light Spectrometer Wavelength nor eRealSign Authenticator shows ads.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*