# Sprale vs duoBooks

The clearest difference is in-app purchases: Sprale at none against duoBooks's 11. Sprale also leads on review sentiment (100% vs 68%). duoBooks's advantage is update cadence (every 2 weeks vs every 39 months) and device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

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

Sprale ships an update every 39 months, duoBooks every 2 weeks. The most recent releases landed on September 27, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Sprale | duoBooks |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (55 ratings)](https://appshunter.io/ios/app/duobooks-language-learning/id1538452253/reviews)** |
| Number of ratings | — | **55** |
| Positive reviews | **100.0% of reviews** | 68.4% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 39 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 24 MB | 53 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 17+ | 12+ |
| Developer | [Rajesh Ramachandrakurup](https://appshunter.io/developer/1487943645) | [PlainProg LLC](https://appshunter.io/developer/1538452255) |

## What reviewers say

### Sprale

[App page](https://appshunter.io/ios/app/sprale/id1487943646)

Discover new words while reading articles and news. This app helps you track, define, and remember vocabulary you encounter, aiding in English language learning. It provides a history of your word lookups and their definitions to reinforce learning.

**Highlights:** Track mystery words from online articles, View definitions of looked-up words, History of word lookups, Reminders for forgotten words, Build English vocabulary, Experimental learning initiative

**Features:** macOS Compatibility

**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 Sprale free?

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

### Is duoBooks free?

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

### Do Sprale or duoBooks have ads?

Neither Sprale nor duoBooks shows ads.

### Which is updated more often, Sprale or duoBooks?

Sprale ships an update every 39 months, and duoBooks every 2 weeks. Most recently, Sprale was updated on September 27, 2026 and duoBooks on October 13, 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.*