# K vs Reflex

The clearest difference is in-app purchases: K at none against Reflex's 5. K also leads on iOS requirement (15.0 vs 17.6). Reflex's advantage is update cadence (every 2 weeks vs every 3 months) and chart position (#132 vs unranked). On price, rating, ads and device support there is nothing between them.

Both are free to download. Reflex sells 5 in-app purchases, starting at $1.99 per month. K asks for nothing beyond the download.

K holds the better App Store score, 3.7 against 3.5. That said, the two scores are not equally well evidenced: Reflex has 23 ratings behind it against 3, so its average is the more settled of the two.

K ships an update every 3 months, Reflex every 2 weeks. The most recent releases landed on October 24, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | K | Reflex |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/k-d-balance/id1389928582/reviews)** | [3.5 (23 ratings)](https://appshunter.io/ios/app/reflex-plr-analyzer/id1412154869/reviews) |
| Number of ratings | 3 | **23** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 weeks** |
| Monetization | **Free** | Subscription |
| Best chart rank | — | **#132** |
| Size | 147 MB | 22 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 12+ | +17 |
| Developer | [King-Devick Test, LLC](https://appshunter.io/developer/424793545) | [Brightlamp, Inc.](https://appshunter.io/developer/1380261827) |

## What reviewers say

### K

[App page](https://appshunter.io/ios/app/k-d-balance/id1389928582)

This medical app helps healthcare professionals assess vestibular dysfunction by measuring balance stance metrics. It uses a device's accelerometer to objectively score balance after voice-guided exercises. Professionals can track patient progress over time.

**Highlights:** Vestibular dysfunction assessment, Measures balance stance metrics, Uses device accelerometer, Objective balance scoring, Longitudinal patient assessment, Voice-guided exercises

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

**In-app purchases:** none


### Reflex

[App page](https://appshunter.io/ios/app/reflex-plr-analyzer/id1412154869)

**Currently charting:** #132 Top Grossing · Medical (US App Store)

This tool measures and tracks pupillary activity using an iPhone camera for quick, 5-second tests. It helps medical professionals monitor patient progress and identify deviations for clinical decision support.

**Highlights:** Pupillary readings via iPhone camera, 5-second test duration, Patient progress tracking, Baseline feature for deviations, Clinical decision support tool, Rapid biomarker validation

**Features:** Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Critical Care Monthly | $1.99 | per month |
| Monthly Subscription | $41.99 | per month |
| Monthly Subscription | $41.99 | per month |
| Yearly Subscription | $419.99 | per year |
| Yearly Subscription | $419.99 | per year |


## Frequently asked questions

### Is K free?

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

### Is Reflex free?

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

### Which has better reviews, K or Reflex?

K is rated higher. K averages 3.7 out of 5 from 3 ratings, while Reflex averages 3.5 from 23 ratings.

### Do K or Reflex have ads?

Neither K nor Reflex shows ads.

### Which is updated more often, K or Reflex?

K ships an update every 3 months, and Reflex every 2 weeks. Most recently, K was updated on October 24, 2026 and Reflex on October 29, 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.*