# Spectrometry vs Professor Index

The clearest difference is rating: Professor Index at 4.5 against Spectrometry's 4.0. Professor Index also leads on update cadence (monthly vs every 6 months) and ratings volume (59 vs 4). Spectrometry's advantage is review sentiment (100% vs 88%) and iOS requirement (11.0 vs 13.0). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Professor Index holds the better App Store score, 4.5 against 4.0. That said, the two scores are not equally well evidenced: Professor Index has 59 ratings behind it against 4, so its average is the more settled of the two. Written reviews complicate that: 100% of Spectrometry's written reviews are positive against 88% of Professor Index's, so the app with the better star average is not the one people write more warmly about.

Spectrometry ships an update every 6 months, Professor Index monthly. The most recent releases landed on October 20, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Spectrometry | Professor Index |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.0 (4 ratings)](https://appshunter.io/ios/app/spectrometry/id893384720/reviews) | **[4.5 (59 ratings)](https://appshunter.io/ios/app/professor-index/id6476449470/reviews)** |
| Number of ratings | 4 | **59** |
| Positive reviews | **100.0% of reviews** | 88.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Monthly** |
| Monetization | Free | Free |
| Size | 43 MB | 57 MB |
| Requires iOS | **11.0** | 13.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [PASCO scientific](https://appshunter.io/developer/361907184) | [Professor Index, LLC](https://appshunter.io/developer/1725377550) |

## What reviewers say

### Spectrometry

[App page](https://appshunter.io/ios/app/spectrometry/id893384720)

This application allows students and teachers to conduct spectrometry experiments using a wireless spectrometer. It measures and analyzes absorbance, transmittance, and fluorescence, supporting full spectrum analysis and Beer's law experiments. The software offers tools for calibration, comparison, and data plotting for educational purposes.

**Highlights:** Measure absorbance, transmittance, fluorescence, Full spectrum analysis, Beer's law and kinetics experiments, Compare multiple spectra, Calibrate dark and reference spectra, Plot absorbance and transmittance, Determine unknown concentration

**In-app purchases:** none


### Professor Index

[App page](https://appshunter.io/ios/app/professor-index/id6476449470)

This app allows college students to rate and review professors and courses, providing insights into teaching effectiveness and course relevance. Students can compare professor profiles and make informed enrollment decisions based on peer feedback.

**Highlights:** Rate and review professors, Get feedback on future professors, Compare professor profiles, Make data-informed enrollment decisions, Gamified review incentives

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Spectrometry free?

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

### Is Professor Index free?

Professor Index is free to download, with no in-app purchases.

### Which has better reviews, Spectrometry or Professor Index?

Professor Index is rated higher. Spectrometry averages 4.0 out of 5 from 4 ratings, while Professor Index averages 4.5 from 59 ratings.

### Do Spectrometry or Professor Index have ads?

Neither Spectrometry nor Professor Index shows ads.

### Which is updated more often, Spectrometry or Professor Index?

Spectrometry ships an update every 6 months, and Professor Index monthly. Most recently, Spectrometry was updated on October 20, 2026 and Professor Index on October 30, 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.*