# P&ID vs Voltius

The clearest difference is in-app purchases: Voltius at none against P&ID's 3. Voltius also leads on iOS requirement (13.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. P&ID sells 3 in-app purchases, starting at $9.99 per month. Voltius asks for nothing beyond the download.

## The numbers

| Metric | P&ID | Voltius |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (6 ratings)](https://appshunter.io/ios/app/p-and-id/id6738429006/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | — |
| Monetization | Free with in-app purchases | — |
| Size | 6 MB | 18 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | iPhone | **iPhone, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) | [Caio Pinheiro](https://appshunter.io/developer/494446833) |

## What reviewers say

### P&ID

[App page](https://appshunter.io/ios/app/p-and-id/id6738429006)

Master the art of reading and interpreting Piping and Instrumentation Diagrams (P&IDs) with this engaging trivia quiz. Test your knowledge of P&ID symbols and their applications through interactive quizzes with detailed explanations and real-world examples. Learn at your own pace with multiple difficulty levels and offline mode.

**Highlights:** Interactive P&ID symbol quizzes, Symbol categorization, Detailed explanations and examples, Multiple difficulty levels, Offline learning mode

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Month | $9.99 | per month |
| 6 months | $19.99 | per 6 months |
| Year | $29.99 | per year |


### Voltius

[App page](https://appshunter.io/ios/app/voltius/id6764050596)

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

**In-app purchases:** none


## Frequently asked questions

### Is P&ID free?

P&ID is free to download, with in-app purchases available.

### Is Voltius free?

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

### Do P&ID or Voltius have ads?

Neither P&ID nor Voltius shows ads.

---

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