# Prime Rush vs 單字雪球

The clearest difference is ads: 單字雪球 at none against Prime Rush's shown. 單字雪球 also leads on update cadence (every 4 days vs every 3 weeks). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Prime Rush sells 1 one-off in-app purchase and 單字雪球 sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Prime Rush ships an update every 3 weeks, 單字雪球 every 4 days. The most recent releases landed on November 9, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | Prime Rush | 單字雪球 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/7000/id6799845340/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | **Every 4 days** |
| Monetization | — | Free |
| Size | 21 MB | 34 MB |
| Requires iOS | 17 | 17.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Ayumu Izumi](https://appshunter.io/developer/1822273057) | [CHENG-LI CHANG](https://appshunter.io/developer/6799845342) |

## What reviewers say

### Prime Rush

[App page](https://appshunter.io/ios/app/prime-rush-math-time-attack/id6755986782)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Plan | $1.99 | one-time |


### 單字雪球

[App page](https://appshunter.io/ios/app/7000/id6799845340)

This app uses spaced repetition to help you master difficult vocabulary. It offers multiple learning modes, including flashcards and quizzes, and includes a large built-in dictionary with example sentences. Progress is synced via iCloud, and the app is designed for users who already know many words.

**Highlights:** Spaced Repetition System (SRS), 18,000+ word built-in vocabulary, Four learning modes: read, quiz, spell, sprint, Morphology lookup and reverse Chinese lookup, Integrated Cambridge Dictionary, iCloud progress synchronization, Home and lock screen widgets

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 記憶線索 | $2.99 | one-time |


## Frequently asked questions

### Is Prime Rush free?

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

### Is 單字雪球 free?

單字雪球 is free to download, with in-app purchases available.

### Do Prime Rush or 單字雪球 have ads?

Prime Rush shows ads; 單字雪球 does not.

### Which is updated more often, Prime Rush or 單字雪球?

Prime Rush ships an update every 3 weeks, and 單字雪球 every 4 days. Most recently, Prime Rush was updated on November 9, 2026 and 單字雪球 on November 6, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*