# Prime Factors vs 영 단어즙

The clearest difference is price: 영 단어즙 at Free against Prime Factors's $0.99. 영 단어즙 also leads on rating (5.0 vs 3.9) and review sentiment (100% vs 79%). Prime Factors's advantage is ratings volume (24 vs 3). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

영 단어즙 is free to download; Prime Factors costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

영 단어즙 holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: Prime Factors has 24 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 79% of Prime Factors's written reviews are positive against 100% of 영 단어즙's.

Prime Factors ships an update every 21 months, 영 단어즙 every 33 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Prime Factors | 영 단어즙 |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [3.9 (24 ratings)](https://appshunter.io/ios/app/prime-factors/id741746948/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/id1480979760/reviews)** |
| Number of ratings | **24** | 3 |
| Positive reviews | 78.6% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 21 months** | Every 33 months |
| Monetization | Free | Free |
| Size | 1 MB | 20 MB |
| Requires iOS | 18.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Paul Hangas](https://appshunter.io/developer/433121902) | [별책](https://appshunter.io/developer/569035377) |

## What reviewers say

### Prime Factors

[App page](https://appshunter.io/ios/app/prime-factors/id741746948)

Explore numbers up to one trillion, with primes clearly marked. Tap any number to reveal its prime factors. Easily navigate to specific numbers using the search function and adjust the display with pinch-to-zoom gestures.

**Highlights:** View numbers up to 1 trillion, Prime numbers highlighted, Tap for prime factors, Search for specific numbers, Pinch and zoom display

**Features:** macOS Compatibility

**In-app purchases:** none


### 영 단어즙

[App page](https://appshunter.io/ios/app/id1480979760)

This app offers a concentrated approach to learning English vocabulary through daily, bite-sized "juice" extractions. It uses a quiz format to help users memorize words, tracking incorrect answers for targeted review. Various visual styles and an integrated English-English dictionary enhance the learning experience.

**Highlights:** Daily vocabulary "juice" extraction, Quiz-based learning format, Tracking of incorrect words for review, Integrated Oxford English-English dictionary, Native speaker pronunciation audio, iCloud data synchronization, Customizable learning deadlines

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

**In-app purchases:** none


## Frequently asked questions

### Is Prime Factors free?

Prime Factors costs $0.99, with no in-app purchases.

### Is 영 단어즙 free?

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

### Which has better reviews, Prime Factors or 영 단어즙?

영 단어즙 is rated higher. Prime Factors averages 3.9 out of 5 from 24 ratings, while 영 단어즙 averages 5.0 from 3 ratings.

### Do Prime Factors or 영 단어즙 have ads?

Neither Prime Factors nor 영 단어즙 shows ads.

### Which is updated more often, Prime Factors or 영 단어즙?

Prime Factors ships an update every 21 months, and 영 단어즙 every 33 months. Most recently, Prime Factors was updated on November 1, 2026 and 영 단어즙 on November 3, 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.*