# PercentTraining vs Structura

The clearest difference is in-app purchases: PercentTraining at none against Structura's 1. PercentTraining also leads on update cadence (daily vs every 4 days) and iOS requirement (15.6 vs 17.0). Structura's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. Structura sells 1 one-off in-app purchase. PercentTraining asks for nothing beyond the download.

PercentTraining ships an update daily, Structura every 4 days. The most recent releases landed on October 30, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | PercentTraining | Structura |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Daily** | Every 4 days |
| Monetization | — | Freemium |
| Size | 3 MB | 100 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Katsuhiko Yao](https://appshunter.io/developer/1543188534) | [SNAPLACE](https://appshunter.io/developer/6790258232) |

## What reviewers say

### PercentTraining

[App page](https://appshunter.io/ios/app/percenttraining/id6744553926)

**Features:** macOS Compatibility

**In-app purchases:** none


### Structura

[App page](https://appshunter.io/ios/app/structura-element-synthesis/id6795030898)

Learn chemical reactions by playing a falling-block puzzle game. Combine elements and ions to build compounds, with over 350 reactions covered. Practice recall with quizzes and tests, and experiment freely with all elements.

**Highlights:** Falling-block puzzle gameplay, Element and ion combination, 356 chemical reactions covered, 46 learning stages, In-game quizzes and tests, Free experiment mode, Visual representation of compounds

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Units | $2.99 | one-time |


## Frequently asked questions

### Is PercentTraining free?

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

### Is Structura free?

Structura is free to download, with in-app purchases available.

### Do PercentTraining or Structura have ads?

PercentTraining shows ads; Structura does not.

### Which is updated more often, PercentTraining or Structura?

PercentTraining ships an update daily, and Structura every 4 days. Most recently, PercentTraining was updated on October 30, 2026 and Structura on November 8, 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.*