# III vs Periodic Table of Elements+

The clearest difference is price: Periodic Table of Elements+ at Free against III's $2.99. Periodic Table of Elements+ also leads on rating (4.7 vs 4.0) and ratings volume (60 vs 1). III's advantage is ads (none vs shown) and review sentiment (100% vs 67%). On in-app purchases and device support there is nothing between them.

Periodic Table of Elements+ is free to download; III costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Periodic Table of Elements+ holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Periodic Table of Elements+ has 60 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 100% of III's written reviews are positive against 67% of Periodic Table of Elements+'s, so the app with the better star average is not the one people write more warmly about.

III ships an update every 17 months, Periodic Table of Elements+ every 7 months. Both last shipped on October 30, 2026.

## The numbers

| Metric | III | Periodic Table of Elements+ |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/iii-v-comp/id475184953/reviews) | **[4.7 (60 ratings)](https://appshunter.io/ios/app/periodic-table-of-elements-plus/id6447423433/reviews)** |
| Number of ratings | 1 | **60** |
| Positive reviews | **100.0% of reviews** | 66.7% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 17 months | **Every 7 months** |
| Monetization | Paid | **Ad-supported** |
| Size | 10 MB | 38 MB |
| Requires iOS | **11.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Takuya Ishikawa](https://appshunter.io/developer/468311118) | [Sonya Marcarelli](https://appshunter.io/developer/409702204) |

## What reviewers say

### III

[App page](https://appshunter.io/ios/app/iii-v-comp/id475184953)

Calculate material properties for III-V compound semiconductors like AlGaInAsP. It determines compositions, lattice constant, strain, bandgap, and effective masses for InP or GaAs substrates.

**Highlights:** III-V compound semiconductor calculations, Material property determination, Composition calculation (x, y, z), Lattice constant and strain analysis, Bandgap and effective mass calculation, Supports InP and GaAs substrates

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

**In-app purchases:** none


### Periodic Table of Elements+

[App page](https://appshunter.io/ios/app/periodic-table-of-elements-plus/id6447423433)

This educational app provides a compact Mendeleev's table with extensive chemical element data. It allows users to create molecular formulas, calculate their mass, and access detailed Wikipedia information for each element. Designed for students and chemistry enthusiasts, it offers VoiceOver accessibility and efficient space utilization.

**Highlights:** Mendeleev's table reference, Molecular formula composer, Molecular mass computation, VoiceOver accessibility, Links to Wikipedia pages, Copyable element information

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is III free?

III costs $2.99, with no in-app purchases.

### Is Periodic Table of Elements+ free?

Periodic Table of Elements+ is free to download, with no in-app purchases.

### Which has better reviews, III or Periodic Table of Elements+?

Periodic Table of Elements+ is rated higher. III averages 4.0 out of 5 from 1 ratings, while Periodic Table of Elements+ averages 4.7 from 60 ratings.

### Do III or Periodic Table of Elements+ have ads?

Periodic Table of Elements+ shows ads; III does not.

### Which is updated more often, III or Periodic Table of Elements+?

III ships an update every 17 months, and Periodic Table of Elements+ every 7 months. Most recently, III was updated on October 30, 2026 and Periodic Table of Elements+ 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.*