# Smart Optometry vs K

The clearest difference is rating: Smart Optometry at 4.4 against K's 3.7. Smart Optometry also leads on ratings volume (529 vs 3) and iOS requirement (13 vs 15.0). K's advantage is in-app purchases (none vs 10). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Smart Optometry sells 10 in-app purchases, starting at $2.99 per month. K asks for nothing beyond the download.

Smart Optometry holds the better App Store score, 4.4 against 3.7. That said, the two scores are not equally well evidenced: Smart Optometry has 529 ratings behind it against 3, so its average is the more settled of the two.

Smart Optometry ships an update every 4 months, K every 3 months. The most recent releases landed on September 20, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Smart Optometry | K |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (529 ratings)](https://appshunter.io/ios/app/smart-optometry/id1053891266/reviews)** | [3.7 (3 ratings)](https://appshunter.io/ios/app/k-d-balance/id1389928582/reviews) |
| Number of ratings | **529** | 3 |
| Positive reviews | 42.3% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 28 MB | 147 MB |
| Requires iOS | **13** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 12+ | 12+ |
| Developer | [Hundred Vision d.o.o.](https://appshunter.io/developer/1053891265) | [King-Devick Test, LLC](https://appshunter.io/developer/424793545) |

## What reviewers say

### Smart Optometry

[App page](https://appshunter.io/ios/app/smart-optometry/id1053891266)

This app offers eye care professionals a suite of 15 interactive and precise digital eye exams for patient screening and testing. It simplifies the examination process with clear guidelines, fast execution, and automated calculations, supporting a more efficient and accurate diagnostic workflow.

**Highlights:** 15 interactive digital eye exams, Automated calculation and diagnosis, Multi-language support, Vertex and visual acuity calculators, Simple and fast user interface, Precise and reliable results

**Features:** Vision Pro support

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRO Monthly Subscription | $2.99 | per month |
| PRO Yearly Subscription | $22.99 | per year |
| Visual Acuity + Test | $1.99 | one-time |
| Red Desaturation Test | $1.99 | one-time |
| Generous Tip | $4.99 | one-time |
| Generous Tip! | $4.99 | one-time |
| Smart Optometry PRO | $9.99 | one-time |
| PRO Bundle | $9.99 | one-time |
| Massive Tip! | $9.99 | one-time |
| Amazing Tip! | $14.99 | one-time |

**What reviewers like**

- 👍 Excellent product
- 👍 Beautifully designed
- 👍 Highly accurate results
- 👍 Super easy to use
- 👍 Masterfully engineered

**What reviewers complain about**

- 🐛 App crashes frequently
- 🐛 App does not open
- 🐛 App stops working
- 🐛 Requires payment for tests
- 🐛 App is full of ads

**Reported bugs**

- App crashes on startup
- App closes automatically after login
- App stops working after update
- Tests demand payment for Pro version
- Visual acuity unit converter plus button not working

**Requested features**

- Update visual acuity unit converter plus button
- Add inches option for measurement
- Provide explanations for test procedures and expected results
- Make Arabic language available
- Allow calibration of acuity test for different distances


### 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


## Frequently asked questions

### Is Smart Optometry free?

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

### Is K free?

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

### Which has better reviews, Smart Optometry or K?

Smart Optometry is rated higher. Smart Optometry averages 4.4 out of 5 from 529 ratings, while K averages 3.7 from 3 ratings.

### Do Smart Optometry or K have ads?

Neither Smart Optometry nor K shows ads.

### Which is updated more often, Smart Optometry or K?

Smart Optometry ships an update every 4 months, and K every 3 months. Most recently, Smart Optometry was updated on September 20, 2026 and K on September 8, 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.*