# OptoDrum vs OKN Drum

The clearest difference is price: OKN Drum at Free against OptoDrum's $4.99. OKN Drum also leads on rating (4.1 vs 2.5) and update cadence (every 2 weeks vs every 3 months). OptoDrum's advantage is in-app purchases (none vs 1) and chart position (#89 vs unranked). On ratings volume, ads, monetization model and device support there is nothing between them.

OKN Drum is free to download; OptoDrum costs $4.99 up front. OKN Drum sells 1 one-off in-app purchase. OptoDrum asks for nothing beyond the download.

OKN Drum holds the better App Store score, 4.1 against 2.5. Both are backed by a comparable volume of ratings — 19 and 16 respectively. Written reviews point the same way: 30% of OptoDrum's written reviews are positive against 46% of OKN Drum's.

OptoDrum ships an update every 3 months, OKN Drum every 2 weeks. The most recent releases landed on October 26, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | OptoDrum | OKN Drum |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [2.5 (19 ratings)](https://appshunter.io/ios/app/optodrum/id374981098/reviews) | **[4.1 (16 ratings)](https://appshunter.io/ios/app/okn-drum-optokinetic/id6474153180/reviews)** |
| Number of ratings | **19** | 16 |
| Positive reviews | 30.4% of reviews | **46.2% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 weeks** |
| Monetization | Paid | Paid |
| Best chart rank | **#89** | — |
| Size | 2 MB | 14 MB |
| Requires iOS | **10.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Linsay Associates, LLC](https://appshunter.io/developer/326305565) | [My Call Bag LLC](https://appshunter.io/developer/1243282862) |

## What reviewers say

### OptoDrum

[App page](https://appshunter.io/ios/app/optodrum/id374981098)

**Currently charting:** #89 Top Paid · Medical (US App Store)

This medical tool offers a digital alternative to traditional optokinetic drums for assessing neurological, otological, and ophthalmological conditions. It allows for easy adjustment of patterns, speed, and width, making it a convenient option for clinical use.

**Highlights:** Digital replacement for optokinetic drums, Adjustable stripe patterns, width, and speed, Five pattern types: stripes, colors, symbols, animals, Intuitive touch controls for speed and stopping, Pinch-to-zoom for pattern width adjustment

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

**In-app purchases:** none


### OKN Drum

[App page](https://appshunter.io/ios/app/okn-drum-optokinetic/id6474153180)

This app offers a digital optokinetic drum for vision testing and exercises. Customize stripe width, speed, and color, with options for pediatric targets. It also features a metronome and camera recording for eye movements.

**Highlights:** Adjustable stripe width and speed, Selectable black or red stripes, Pediatric targets (puppies, dinosaurs, animals), Full-screen mode, Integrated metronome, Record eye movements with camera, Upload custom images for drum

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $4.99 | one-time |


## Frequently asked questions

### Is OptoDrum free?

OptoDrum costs $4.99, with no in-app purchases.

### Is OKN Drum free?

OKN Drum is free to download, with in-app purchases available.

### Which has better reviews, OptoDrum or OKN Drum?

OKN Drum is rated higher. OptoDrum averages 2.5 out of 5 from 19 ratings, while OKN Drum averages 4.1 from 16 ratings.

### Do OptoDrum or OKN Drum have ads?

Neither OptoDrum nor OKN Drum shows ads.

### Which is updated more often, OptoDrum or OKN Drum?

OptoDrum ships an update every 3 months, and OKN Drum every 2 weeks. Most recently, OptoDrum was updated on October 26, 2026 and OKN Drum on October 25, 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.*