# III vs Periodic Table PRO

The clearest difference is review sentiment: III at 100% against Periodic Table PRO's 50%. III also leads on in-app purchases (none vs 8) and iOS requirement (11.0 vs 15.0). Periodic Table PRO's advantage is price (Free vs $2.99) and rating (4.6 vs 4.0). On ads, monetization model and device support there is nothing between them.

Periodic Table PRO is free to download; III costs $2.99 up front. Periodic Table PRO sells 8 one-off in-app purchases. III asks for nothing beyond the download.

Periodic Table PRO holds the better App Store score, 4.6 against 4.0. That said, the two scores are not equally well evidenced: Periodic Table PRO has 87 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 50% of Periodic Table PRO'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 PRO every 6 weeks. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | III | Periodic Table PRO |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/iii-v-comp/id475184953/reviews) | **[4.6 (87 ratings)](https://appshunter.io/ios/app/periodic-table-pro/id1601545941/reviews)** |
| Number of ratings | 1 | **87** |
| Positive reviews | **100.0% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 17 months | **Every 6 weeks** |
| Monetization | Paid | Paid |
| Size | 10 MB | 206 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) | [AGILE FLEX TECH](https://appshunter.io/developer/1601049602) |

## 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 PRO

[App page](https://appshunter.io/ios/app/periodic-table-pro/id1601545941)

Explore a virtual chemistry lab with interactive experiments and detailed information on all chemical elements. Features include atom structure simulations, downloadable PDFs, and studying analytics to enhance learning. Supports multiple languages and offers a cohesive, functional design.

**Highlights:** Virtual chemistry lab with experiments, Detailed chemical element information, Atom structure simulations, Downloadable element PDFs, Studying analytics, Multi-language support

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SPECIAL OFFER! | $9.99 | one-time |
| Chernobyl experiments | $9.99 | one-time |
| Explosive experiments | $9.99 | one-time |
| Funny experiments | $9.99 | one-time |
| Experiments with fire | $9.99 | one-time |
| Gas bubbles experiments | $9.99 | one-time |
| Melting experiments | $9.99 | one-time |
| Oxidation experiments | $9.99 | one-time |


## Frequently asked questions

### Is III free?

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

### Is Periodic Table PRO free?

Periodic Table PRO is free to download, with in-app purchases available.

### Which has better reviews, III or Periodic Table PRO?

Periodic Table PRO is rated higher. III averages 4.0 out of 5 from 1 ratings, while Periodic Table PRO averages 4.6 from 87 ratings.

### Do III or Periodic Table PRO have ads?

Neither III nor Periodic Table PRO shows ads.

### Which is updated more often, III or Periodic Table PRO?

III ships an update every 17 months, and Periodic Table PRO every 6 weeks. Most recently, III was updated on November 6, 2026 and Periodic Table PRO on November 3, 2026.

---

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