# KPD vs Introvert

The clearest difference is in-app purchases: KPD at none against Introvert's 10. KPD also leads on rating (5.0 vs 4.7). Introvert's advantage is update cadence (every 2 weeks vs every 5 months) and ratings volume (837 vs 1). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Introvert sells 10 in-app purchases, starting at $6.99 per month. KPD asks for nothing beyond the download.

KPD holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Introvert has 837 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 22% of KPD's written reviews are positive against 44% of Introvert's, so the app with the better star average is not the one people write more warmly about.

KPD ships an update every 5 months, Introvert every 2 weeks. The most recent releases landed on August 11, 2026 and September 26, 2026 respectively.

## The numbers

| Metric | KPD | Introvert |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/kpd-bio/id1229570219/reviews)** | [4.7 (837 ratings)](https://appshunter.io/ios/app/introvert-self-development/id1561586203/reviews) |
| Number of ratings | 1 | **837** |
| Positive reviews | 22.2% of reviews | **43.8% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 10 MB | 488 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [НОУ МЦНМО](https://appshunter.io/developer/1235476259) | [ArtIntrovert LLC](https://appshunter.io/developer/1727512095) |

## What reviewers say

### KPD

[App page](https://appshunter.io/ios/app/kpd-bio/id1229570219)

This app provides a comprehensive Russian-language electronic version of a leading biology textbook, ideal for high school students and teachers. It includes supplementary materials for practice and scientific article analysis, offering structured learning from basic to advanced concepts.

**Highlights:** Russian electronic textbook, Student Study Guide included, Inquiry in Action guide, University-level biology content, Illustrations and diagrams, Self-check questions and tasks, Electronic glossary search

**Features:** macOS Compatibility

**In-app purchases:** none


### Introvert

[App page](https://appshunter.io/ios/app/introvert-self-development/id1561586203)

Access concise, 20-minute lectures summarizing books and studies on diverse topics. Earn certificates and track progress with background playback and offline downloads. Join a global community focused on self-growth.

**Highlights:** 20-minute lectures, Summaries of books and studies, 13+ topics covered, Certificates and progress tracking, Offline downloads, Background playback

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Тариф 1 месяц | $6.99 | per month |
| Monthly rate | $6.99 | per month |
| 1 month subscription | $6.99 | per month |
| 1 year subscription | $49.99 | per year |
| Лекция | $0.99 | one-time |
| Лекция | $4.99 | one-time |
| Видеолекция | $9.99 | one-time |
| Профильный курс | $42.99 | one-time |
| Профильный курс | $49.99 | one-time |
| Профильный курс | $54.99 | one-time |

**What reviewers like**

- 🚀 Interesting and informative lectures
- 👍 Convenient and intuitive interface
- 💡 Gamification elements like rating and rewards
- 🤖 Helpful AI assistant
- 🌐 Diverse range of topics covered

**What reviewers complain about**

- 🐛 Frequent bugs and glitches
- 🔌 Issues with offline mode and downloads
- 💸 Unclear subscription management and cancellation
- 🔍 Lack of search and filtering options
- 🔊 Poor audio/video synchronization

**Reported bugs**

- White screen issues
- Login and registration problems
- Inconsistent progress tracking
- Subscription billing errors
- Compatibility issues on older devices

**Requested features**

- Option to adjust text size
- Improved offline capabilities
- Seamless integration between app and website
- More personalization options
- Subtitles and transcripts for lectures


## Frequently asked questions

### Is KPD free?

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

### Is Introvert free?

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

### Which has better reviews, KPD or Introvert?

KPD is rated higher. KPD averages 5.0 out of 5 from 1 ratings, while Introvert averages 4.7 from 837 ratings.

### Do KPD or Introvert have ads?

Neither KPD nor Introvert shows ads.

### Which is updated more often, KPD or Introvert?

KPD ships an update every 5 months, and Introvert every 2 weeks. Most recently, KPD was updated on August 11, 2026 and Introvert on September 26, 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.*