# Kois Reader vs PerioCalc

The clearest difference is review sentiment: PerioCalc at 100% against Kois Reader's 20%. PerioCalc also leads on rating (5.0 vs 3.6) and update cadence (every 3 months vs every 9 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

PerioCalc holds the better App Store score, 5.0 against 3.6. Both are backed by a comparable volume of ratings — 10 and 6 respectively. Written reviews point the same way: 20% of Kois Reader's written reviews are positive against 100% of PerioCalc's.

Kois Reader ships an update every 9 months, PerioCalc every 3 months. The most recent releases landed on August 14, 2026 and June 7, 2026 respectively.

## The numbers

| Metric | Kois Reader | PerioCalc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.6 (10 ratings)](https://appshunter.io/ios/app/kois-reader/id1132199528/reviews) | **[5.0 (6 ratings)](https://appshunter.io/ios/app/periocalc/id6470758932/reviews)** |
| Number of ratings | **10** | 6 |
| Positive reviews | 20.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 3 months** |
| Monetization | Free | Free |
| Size | 75 MB | 22 MB |
| Requires iOS | 14.0 | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Kois Center](https://appshunter.io/developer/513136947) | [Rutgers, The State University of New Jersey](https://appshunter.io/developer/458425733) |

## What reviewers say

### Kois Reader

[App page](https://appshunter.io/ios/app/kois-reader/id1132199528)

Access Kois Course materials, including manuals, checklists, and videos. Features live polling, automatic note backup and syncing across devices, and the ability to share notes with other participants. Requires course attendance for full access.

**Highlights:** Access course manuals and videos, Live in-course polling, Automatic note backup and sync, Share notes with participants, Browse page thumbnails, Navigation history

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

**In-app purchases:** none


### PerioCalc

[App page](https://appshunter.io/ios/app/periocalc/id6470758932)

This educational tool assists dental students and professionals in understanding and applying the latest periodontal classification guidelines for staging and grading periodontitis and peri-implantitis. It offers instant results for case-based learning, focusing on the 2018 Classification.

**Highlights:** Periodontal classification learning, Staging and grading of periodontitis, Peri-implantitis classification, Case-based learning tool, Instant results, Based on 2018 Classification

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Kois Reader free?

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

### Is PerioCalc free?

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

### Which has better reviews, Kois Reader or PerioCalc?

PerioCalc is rated higher. Kois Reader averages 3.6 out of 5 from 10 ratings, while PerioCalc averages 5.0 from 6 ratings.

### Do Kois Reader or PerioCalc have ads?

Neither Kois Reader nor PerioCalc shows ads.

### Which is updated more often, Kois Reader or PerioCalc?

Kois Reader ships an update every 9 months, and PerioCalc every 3 months. Most recently, Kois Reader was updated on August 14, 2026 and PerioCalc on June 7, 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.*