# PSS EVO vs Nitrox by Envivia

The clearest difference is in-app purchases: PSS EVO at none against Nitrox by Envivia's 4. PSS EVO also leads on iOS requirement (10.0 vs 15.6). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Nitrox by Envivia sells 4 in-app purchases, starting at $9.99 per year. PSS EVO asks for nothing beyond the download.

PSS EVO ships an update every 3 months, Nitrox by Envivia every 6 weeks. The most recent releases landed on September 24, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | PSS EVO | Nitrox by Envivia |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nitrox-by-envivia/id1613770132/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 5 MB | 72 MB |
| Requires iOS | **10.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Margherita Aucelli](https://appshunter.io/developer/904666795) | [ENVIVIA](https://appshunter.io/developer/1583628615) |

## What reviewers say

### PSS EVO

[App page](https://appshunter.io/ios/app/pss-evo/id1361482398)

This app serves as a digital learning hub, offering educational content for users. It provides a centralized platform for accessing various learning materials and resources.

**Highlights:** E-learning center, Access educational content, Centralized learning platform, Educational resources

**Features:** macOS Compatibility

**In-app purchases:** none


### Nitrox by Envivia

[App page](https://appshunter.io/ios/app/nitrox-by-envivia/id1613770132)

This app is a premium digital guide for Nitrox diving, offering educational content and calculation tools to optimize dives. It helps divers understand oxygen limits, plan dives using gradient factors, and prepare for certification.

**Highlights:** Calculate MOD (Maximum Operating Depth), Manage oxygen partial pressure (PPO₂), Optimize Nitrox dive planning, Understand oxygen-related physiological limits, Prepare for Nitrox certification, Multilingual support

**Features:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $9.99 | per year |
| Thank you | $1.99 | one-time |
| Popular | $9.99 | one-time |
| Generous | $49.99 | one-time |


## Frequently asked questions

### Is PSS EVO free?

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

### Is Nitrox by Envivia free?

Nitrox by Envivia is free to download, with in-app purchases available.

### Do PSS EVO or Nitrox by Envivia have ads?

Neither PSS EVO nor Nitrox by Envivia shows ads.

### Which is updated more often, PSS EVO or Nitrox by Envivia?

PSS EVO ships an update every 3 months, and Nitrox by Envivia every 6 weeks. Most recently, PSS EVO was updated on September 24, 2026 and Nitrox by Envivia on September 20, 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.*