# King vs Optics Trainer

The clearest difference is rating: King at 5.0 against Optics Trainer's 4.5. King also leads on in-app purchases (none vs 3) and ads (none vs shown). Optics Trainer's advantage is update cadence (every 8 days vs every 2 months) and ratings volume (302 vs 2). On price and device support there is nothing between them.

Both are free to download. Optics Trainer sells 3 in-app purchases, starting at $4.99 per 7 days. King asks for nothing beyond the download.

King holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Optics Trainer has 302 ratings behind it against 2, so its average is the more settled of the two.

King ships an update every 2 months, Optics Trainer every 8 days. The most recent releases landed on October 2, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | King | Optics Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/king-devick-test/id1033607954/reviews)** | [4.5 (302 ratings)](https://appshunter.io/ios/app/optics-trainer-vision-and-brain/id1471943589/reviews) |
| Number of ratings | 2 | **302** |
| Positive reviews | — | 64.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Every 8 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 243 MB | 476 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) | [Optics Trainer LLC](https://appshunter.io/developer/898519375) |

## 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


### Optics Trainer

[App page](https://appshunter.io/ios/app/optics-trainer-vision-and-brain/id1471943589)

Enhance your visual skills with a variety of engaging games and personalized daily workouts. Improve convergence, divergence, stereo acuity, and binocular fusion. Test and strengthen visual memory, tracking, and peripheral vision for sharper focus.

**Highlights:** Vision therapy and training, 28+ engaging games, Personalized daily workouts, Improve convergence and divergence, Enhance stereo acuity and binocular fusion, Test visual memory and tracking

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Subscription | $4.99 | per 7 days |
| Monthly Subscription | $14.99 | per month |
| Annual Subscription | $149.99 | per year |

**What reviewers like**

- 👍 Fun and engaging games
- 💡 Helpful for vision therapy
- ✅ Clearly explains objectives
- 🚀 Improves focus and coordination
- 😊 Makes eye training enjoyable

**What reviewers complain about**

- 💸 Expensive subscription model
- 😠 Overwhelming and intrusive ads
- ❌ Free version unusable due to ads
- 📉 Poorly programmed exercises
- 🚫 No scientific evidence for some claims

**Reported bugs**

- Number flip game has blank tiles
- Flower power stopped working
- Letter delivery letter goes off-screen
- Attention exercises stuck on level one
- Ice flow impossible to level up

**Requested features**

- Customize peripheral vision symbols
- Option to change symbol colors
- Adjust number of targets in Dynamic Acuity
- Add introductory level for Dynamic Acuity
- Allow offline play in free version


## Frequently asked questions

### Is King free?

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

### Is Optics Trainer free?

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

### Which has better reviews, King or Optics Trainer?

King is rated higher. King averages 5.0 out of 5 from 2 ratings, while Optics Trainer averages 4.5 from 302 ratings.

### Do King or Optics Trainer have ads?

Optics Trainer shows ads; King does not.

### Which is updated more often, King or Optics Trainer?

King ships an update every 2 months, and Optics Trainer every 8 days. Most recently, King was updated on October 2, 2026 and Optics Trainer on October 15, 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.*