# NASA PVT+ vs PISON

The clearest difference is update cadence: PISON at every 3 weeks against NASA PVT+'s every 3 months. PISON also leads on rating (5.0 vs 4.8). NASA PVT+'s advantage is iOS requirement (13.6 vs 15.0). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

PISON holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 10 and 7 respectively.

NASA PVT+ ships an update every 3 months, PISON every 3 weeks. The most recent releases landed on August 15, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | NASA PVT+ | PISON |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (10 ratings)](https://appshunter.io/ios/app/nasa-pvt-plus/id1146834402/reviews) | **[5.0 (7 ratings)](https://appshunter.io/ios/app/pison/id6475786964/reviews)** |
| Number of ratings | **10** | 7 |
| Positive reviews | 25.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 31 MB | 64 MB |
| Requires iOS | **13.6** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [NASA](https://appshunter.io/developer/355542146) | [Pison Technology](https://appshunter.io/developer/1705268860) |

## What reviewers say

### NASA PVT+

[App page](https://appshunter.io/ios/app/nasa-pvt-plus/id1146834402)

This app provides a validated tool for conducting psychomotor vigilance tests, crucial for sleep, alertness, and performance research. It offers multiple study frameworks, including simple tests, basic multi-day studies, and specialized aviation research protocols.

**Highlights:** Psychomotor Vigilance Test (PVT), Karolinska Sleepiness Scale (KSS), Sleep Diary, Simple PVT mode, Basic Study framework, Aviation Study framework

**Features:** Vision Pro support

**In-app purchases:** none


### PISON

[App page](https://appshunter.io/ios/app/pison/id6475786964)

This app provides insights into your cognitive and physical performance using data from compatible smartwatches. It helps you understand readiness, mental agility, and focus, with advanced metrics for sleep, stress, and health available through membership tiers.

**Highlights:** Cognitive performance metrics (Readiness, Agility, Focus), Sleep and fatigue tracking, Stress and health monitoring, Fitness metrics (respiratory rate, calories), Community leaderboards and groups, Insights from neural sensor technology

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

**In-app purchases:** none


## Frequently asked questions

### Is NASA PVT+ free?

NASA PVT+ is free to download, with no in-app purchases.

### Is PISON free?

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

### Which has better reviews, NASA PVT+ or PISON?

PISON is rated higher. NASA PVT+ averages 4.8 out of 5 from 10 ratings, while PISON averages 5.0 from 7 ratings.

### Do NASA PVT+ or PISON have ads?

Neither NASA PVT+ nor PISON shows ads.

### Which is updated more often, NASA PVT+ or PISON?

NASA PVT+ ships an update every 3 months, and PISON every 3 weeks. Most recently, NASA PVT+ was updated on August 15, 2026 and PISON on September 23, 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.*