# World's Key vs Corrsy

The clearest difference is rating: Corrsy at 4.4 against World's Key's 3.8. Corrsy also leads on review sentiment (88% vs 55%) and iOS requirement (13.4 vs 16.6). World's Key's advantage is in-app purchases (none vs 6) and ratings volume (317 vs 78). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Corrsy sells 6 one-off in-app purchases. World's Key asks for nothing beyond the download.

Corrsy holds the better App Store score, 4.4 against 3.8. Both are backed by a comparable volume of ratings — 317 and 78 respectively. Written reviews point the same way: 55% of World's Key's written reviews are positive against 88% of Corrsy's.

World's Key ships an update every 8 days, Corrsy weekly. Both last shipped on October 24, 2026.

## The numbers

| Metric | World's Key | Corrsy |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.8 (317 ratings)](https://appshunter.io/ios/app/worlds-key/id1494964110/reviews) | **[4.4 (78 ratings)](https://appshunter.io/ios/app/corrsy/id1587328977/reviews)** |
| Number of ratings | **317** | 78 |
| Positive reviews | 54.5% of reviews | **88.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 days | **Weekly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 35 MB | 54 MB |
| Requires iOS | 16.6 | **13.4** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Mohammad Bzeih](https://appshunter.io/developer/1494964109) | [Corrsy Oy Ltd](https://appshunter.io/developer/1569577220) |

## What reviewers say

### World's Key

[App page](https://appshunter.io/ios/app/worlds-key/id1494964110)

This interactive educational app offers audio-visual lessons and exercises for English and Science curricula for Kindergarten and Primary levels. Students can access engaging content and assessments through an online account, supplementing their printed books.

**Highlights:** Interactive audio-visual lessons, English and Science curricula, Kindergarten and Primary levels, Interactive exercises, Assessments for lessons, Online account access

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 👍 Educational value for students
- 😍 Highly praised by young students
- 👍 Useful for international schools
- 👍 Good content for learning
- 👍 App is beneficial for international students

**What reviewers complain about**

- 😡 App is very slow
- 😡 App crashes frequently
- 😡 App is not user-friendly
- 😡 App is old and outdated
- 😡 App is heavy and lags

**Reported bugs**

- App logs out when accessing videos
- App freezes and doesn't calculate views
- App has errors in exam time calculation
- App doesn't open
- App crashes when opening or solving lessons

**Requested features**

- Add video playback speed control
- Improve app's responsiveness and speed
- Continuous improvement and development of the app
- Fix bugs and glitches
- Update the app to be more modern


### Corrsy

[App page](https://appshunter.io/ios/app/corrsy/id1587328977)

An interactive educational app offering private lessons for Iraqi curricula, from middle school to high school. Features engaging videos, concise summaries, and smart tests explained by top Iraqi educators using modern Finnish teaching methods. Ideal for quick revision before exams.

**Highlights:** Interactive private lessons, Lessons for Iraqi curricula (grades 7-12), Taught by top Iraqi educators, Modern Finnish teaching methods, Concise and fast-paced lessons, Engaging educational videos, Lesson summaries, Smart comprehension tests

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Dinar Pack 1 | $1.59 | one-time |
| Dinar Pack 2 | $3.89 | one-time |
| Dinar Pack 3 | $9.99 | one-time |
| Dinar Pack 5 | $38.49 | one-time |
| Dinar Pack 4 | $76.00 | one-time |
| Dinar Pack 6 - 250000 | $190.99 | one-time |


## Frequently asked questions

### Is World's Key free?

World's Key is free to download, with no in-app purchases.

### Is Corrsy free?

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

### Which has better reviews, World's Key or Corrsy?

Corrsy is rated higher. World's Key averages 3.8 out of 5 from 317 ratings, while Corrsy averages 4.4 from 78 ratings.

### Do World's Key or Corrsy have ads?

Neither World's Key nor Corrsy shows ads.

### Which is updated more often, World's Key or Corrsy?

World's Key ships an update every 8 days, and Corrsy weekly. Most recently, World's Key was updated on October 24, 2026 and Corrsy on October 24, 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.*