Verticality Test vs OKN Drum
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Verticality Test
Assess verticality, horizontality, and depth perception using your iOS device. This app offers a novel methodology for performing these tests anywhere, under any lighting conditions. A tvOS version is available for classical testing on Apple TV.
- Verticality perception tests
- Horizontality perception tests
- Profundity perception tests
- Novel testing methodology
- iOS device mobility
- tvOS version available
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With Verticality test you can perform easily the verticality perception, horizontality perception and profundity perception tests with all the mobility advantages of your iOS device. We developed a new methodology to allow you to perform the tests at any location with any illumination. For a classical performance of the tests you can use the tvOS version on an AppleTV 4thGen. Verticality and horizontality perception tests are well known medical tests to measure the otolithic function. WARNING: Verticality Test is not a medical device
OKN Drum
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.
- 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
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IN-APP PURCHASE REQUIRED FOR USE · OKN Drum Pro provides an Optokinetic Nystagmus (OKN) Drum featuring multiple modes for optokinetic testing and exercises. Users can adjust the stripe width to their preference using the pinch-to-zoom functionality. · The speed of the OKN stripes is easily adjustable, enabling quick increases or decreases as desired. · Users have the option to select either black or red stripes to suit their visual requirements. · Includes multiple pediatric targets, such as puppies, dinosaurs, and various animal targets. · By tapping the stripes, users can enter full-screen mode for an immersive experience. · A metronome is also available to assist with timing exercises, enhancing the overall utility of the app for therapeutic and testing purposes. · Graph eye movements with pupil tracking · Record eye movements with the front facing camera · Upload images for a custom OKN drum · Flick the OKN graphic to simulate rotating an OKN drum This app is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or a qualified healthcare provider before making any medical decisions. If you think you may have a medical emergency, call emergency services immediately.
Screenshots
Verdict
Verticality Test and OKN Drum both sit at 4.0 stars, but that hides the real split: 46% of OKN Drum's written reviews are positive against 0% of Verticality Test's. OKN Drum also leads on update cadence (every 2 weeks vs every 4 months) and ratings volume (16 vs 2). Verticality Test's advantage is in-app purchases (none vs 1) and device support (4 vs 2). On price, rating and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. OKN Drum sells 1 one-off in-app purchase. Verticality Test asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.0 for Verticality Test against 4.1 for OKN Drum. That said, the two scores are not equally well evidenced: OKN Drum has 16 ratings behind it against 2, so its average is the more settled of the two. Written reviews are what separate them: 0% of Verticality Test's written reviews are positive against 46% of OKN Drum's.
Verticality Test ships an update every 4 months, OKN Drum every 2 weeks. The most recent releases landed on October 2, 2026 and October 25, 2026 respectively.
| Parameter | Verticality Test | OKN Drum |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (2 ratings) | 4.1 (16 ratings) — better |
| Positive reviews | 0.0% of reviews | 46.2% of reviews — better |
| Number of ratings | 2 | 16 — better |
| Update frequency | Every 4 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad, iPod, Apple TV — better | iPhone, iPad |
| Requires iOS | 11.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 62 MB | 14 MB |
| Age rating | 17+ | 4+ |
| Developer | Jorge Alberto Rey Martinez | My Call Bag LLC |
Customer experience
Verticality Test
OKN Drum
In-app purchases
Verticality Test
No in-app purchases
OKN Drum
- Lifetime Access$4.99
Questions
Is Verticality Test free?
Is OKN Drum free?
Which has better reviews, Verticality Test or OKN Drum?
Do Verticality Test or OKN Drum have ads?
Which is updated more often, Verticality Test or OKN Drum?
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