# Kotobee Reader vs duoBooks

The clearest difference is rating: duoBooks at 4.7 against Kotobee Reader's 3.6. duoBooks also leads on update cadence (every 2 weeks vs every 2 months) and review sentiment (69% vs 50%). Kotobee Reader's advantage is in-app purchases (none vs 11) and iOS requirement (13.0 vs 15.0). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. duoBooks sells 11 in-app purchases, starting at $2.99 per month. Kotobee Reader asks for nothing beyond the download.

duoBooks holds the better App Store score, 4.7 against 3.6. Both are backed by a comparable volume of ratings — 22 and 48 respectively. Written reviews point the same way: 50% of Kotobee Reader's written reviews are positive against 69% of duoBooks's.

Kotobee Reader ships an update every 2 months, duoBooks every 2 weeks. The most recent releases landed on September 20, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Kotobee Reader | duoBooks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.6 (22 ratings)](https://appshunter.io/ios/app/kotobee-reader/id1109764395/reviews) | **[4.7 (48 ratings)](https://appshunter.io/ios/app/duobooks-language-learning/id1538452253/reviews)** |
| Number of ratings | 22 | **48** |
| Positive reviews | 50.0% of reviews | **68.6% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 14 MB | 54 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Vijua](https://appshunter.io/developer/843229887) | [PlainProg LLC](https://appshunter.io/developer/1538452255) |

## What reviewers say

### Kotobee Reader

[App page](https://appshunter.io/ios/app/kotobee-reader/id1109764395)

This app provides an ad-free digital reading experience for interactive ebooks. It supports EPUB 3.0, offers note-taking, highlighting, bookmarking, and text-to-speech functionalities. Access a free digital library for offline reading.

**Highlights:** EPUB 3.0 support, Note-taking and highlighting, Bookmarking, Aggregate annotations to PDF, Offline reading, Text-to-speech, Google lookup

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

**In-app purchases:** none


### duoBooks

[App page](https://appshunter.io/ios/app/duobooks-language-learning/id1538452253)

Read any book in any language with instant translation and detailed word explanations. Build your vocabulary with a personal dictionary and spaced repetition tools. Improve pronunciation with audio voiceovers and master new languages through immersive bilingual reading.

**Highlights:** Instant translation of any book, Personalized vocabulary dictionary, Spaced repetition for memorization, Audio voiceovers for pronunciation, Bilingual parallel text reading, EPUB reader for custom files

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

**In-app purchases (11)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Plan | $2.99 | per month |
| Full Plan | $6.99 | per month |
| Full Plan | $17.99 | per year |
| 6 Month Full Plan | $19.99 | per 6 months |
| Full Yearly Plan | $29.99 | per year |
| War and Peace | $0.99 | one-time |
| Silver Blaze | $0.99 | one-time |
| On The River | $0.99 | one-time |
| Clochette | $0.99 | one-time |
| The Fishing Hole | $0.99 | one-time |
| Alice in Wonderland | $0.99 | one-time |


## Frequently asked questions

### Is Kotobee Reader free?

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

### Is duoBooks free?

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

### Which has better reviews, Kotobee Reader or duoBooks?

duoBooks is rated higher. Kotobee Reader averages 3.6 out of 5 from 22 ratings, while duoBooks averages 4.7 from 48 ratings.

### Do Kotobee Reader or duoBooks have ads?

Neither Kotobee Reader nor duoBooks shows ads.

### Which is updated more often, Kotobee Reader or duoBooks?

Kotobee Reader ships an update every 2 months, and duoBooks every 2 weeks. Most recently, Kotobee Reader was updated on September 20, 2026 and duoBooks on September 21, 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.*