# iRotorBalancer vs Light Spectrometer Wavelength

The clearest difference is price: Light Spectrometer Wavelength at Free against iRotorBalancer's $799.99. Light Spectrometer Wavelength also leads on ratings volume (92 vs 1) and device support (3 vs 1). iRotorBalancer's advantage is rating (5.0 vs 4.2) and iOS requirement (11.0 vs 15.0). On update cadence, ads and in-app purchases there is nothing between them.

Light Spectrometer Wavelength is free to download; iRotorBalancer costs $799.99 up front. iRotorBalancer sells 2 one-off in-app purchases and Light Spectrometer Wavelength sells 4 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

iRotorBalancer 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 92 ratings behind it against 1, so its average is the more settled of the two.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on June 24, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | iRotorBalancer | Light Spectrometer Wavelength |
| --- | --- | --- |
| Price | $799.99 | **Free** |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/irotorbalancer/id523471219/reviews)** | [4.2 (92 ratings)](https://appshunter.io/ios/app/light-spectrometer-wavelength/id6450930820/reviews) |
| Number of ratings | 1 | **92** |
| Positive reviews | — | 71.9% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 18 MB | 43 MB |
| Requires iOS | **11.0** | 15.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Motionics, LLC](https://appshunter.io/developer/424498959) | [Contechity AB](https://appshunter.io/developer/1649290454) |

## What reviewers say

### iRotorBalancer

[App page](https://appshunter.io/ios/app/irotorbalancer/id523471219)

This technical tool assists in balancing rotating machinery using single or two-plane methods. It connects to external hardware to measure vibration amplitude and phase, then calculates necessary correction weights and their positions. Reports can be generated and emailed.

**Highlights:** Single-plane balancing (Vector & Four-Runs methods), Two-plane balancing (Influence Coefficients), Real-time waveform and FFT spectrum display, Automatic 1X peak amplitude and phase selection, Polar plot and weight location graphics, Report generation with plots, data, and images

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Custom Report Header and Logo | $49.99 | one-time |
| Two-Plane Overhung Rotor Balancing | $249.99 | one-time |


### 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 |


## Frequently asked questions

### Is iRotorBalancer free?

iRotorBalancer costs $799.99, and also offers in-app purchases.

### Is Light Spectrometer Wavelength free?

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

### Which has better reviews, iRotorBalancer or Light Spectrometer Wavelength?

iRotorBalancer is rated higher. iRotorBalancer averages 5.0 out of 5 from 1 ratings, while Light Spectrometer Wavelength averages 4.2 from 92 ratings.

### Do iRotorBalancer or Light Spectrometer Wavelength have ads?

Neither iRotorBalancer nor Light Spectrometer Wavelength shows ads.

### Which is updated more often, iRotorBalancer or Light Spectrometer Wavelength?

iRotorBalancer ships an update every 2 months, and Light Spectrometer Wavelength every 2 months. Most recently, iRotorBalancer was updated on June 24, 2026 and Light Spectrometer Wavelength on September 22, 2026.

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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.*