# King vs Prevent

The clearest difference is ratings volume: Prevent at 9 against King's 2. King's advantage is iOS requirement (9.0 vs 16.4). On price, rating, update cadence and ads there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for King against 5.0 for Prevent. Both are backed by a comparable volume of ratings — 2 and 9 respectively.

King ships an update every 2 months, Prevent monthly. The most recent releases landed on June 11, 2026 and September 1, 2026 respectively.

## The numbers

| Metric | King | Prevent |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/king-devick-test/id1033607954/reviews) | [5.0 (9 ratings)](https://appshunter.io/ios/app/prevent/id1121375378/reviews) |
| Number of ratings | 2 | **9** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Free | Free |
| Size | 243 MB | 46 MB |
| Requires iOS | **9.0** | 16.4 |
| Devices | iPad | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [King-Devick Test LLC](https://appshunter.io/developer/424793545) | [Prevent Biometrics, Inc](https://appshunter.io/developer/1121375377) |

## What reviewers say

### King

[App page](https://appshunter.io/ios/app/king-devick-test/id1033607954)

This app provides a quick and objective sideline concussion screening test for athletes. It helps identify potential concussions by assessing eye movements, attention, and concentration through a simple number-reading exercise. Requires an existing King-Devick Online account.

**Highlights:** Objective sideline concussion screening, Assess eye movements and attention, Administer baseline and post-injury tests, Works offline, Suitable for ages 5+

**Features:** macOS Compatibility

**In-app purchases:** none


### Prevent

[App page](https://appshunter.io/ios/app/prevent/id1121375378)

This app pairs with a special mouthguard to monitor head impacts in real-time. It provides detailed data on acceleration, direction, and load for each impact, helping teams and parents assess player safety and identify athletes needing evaluation.

**Highlights:** Real-time head impact data, Linear and rotational acceleration tracking, Impact direction and location analysis, Impact Load measurement, Player and team data views, Live alerts for high-magnitude impacts

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

**In-app purchases:** none


## Frequently asked questions

### Is King free?

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

### Is Prevent free?

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

### Which has better reviews, King or Prevent?

King and Prevent are both rated 5.0 out of 5 on the App Store, from 2 and 9 ratings respectively.

### Do King or Prevent have ads?

Neither King nor Prevent shows ads.

### Which is updated more often, King or Prevent?

King ships an update every 2 months, and Prevent monthly. Most recently, King was updated on June 11, 2026 and Prevent on September 1, 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.*