# Serial 7s vs 초성퀴즈!

The clearest difference is update cadence: 초성퀴즈! at every 3 weeks against Serial 7s's every 5 months. 초성퀴즈! also leads on iOS requirement (13.0 vs 15.0). On ads, in-app purchases and device support there is nothing between them.

Serial 7s ships an update every 5 months, 초성퀴즈! every 3 weeks. The most recent releases landed on October 20, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Serial 7s | 초성퀴즈! |
| --- | --- | --- |
| Price | **Free** | — |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/serial-7s/id6480178276/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 5 months | **Every 3 weeks** |
| Monetization | Ad-supported | — |
| Size | 42 MB | 224 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 9+ | 4+ |
| Developer | [HFX Lab](https://appshunter.io/developer/1139262927) | [jingyoung lee](https://appshunter.io/developer/1823833079) |

## What reviewers say

### Serial 7s

[App page](https://appshunter.io/ios/app/serial-7s/id6480178276)

This game challenges you to rapidly subtract 7 from a starting number until you can no longer continue. It's based on a cognitive test used to assess attention and memory, with consistent play potentially improving brain skills and helping to prevent cognitive decline.

**Highlights:** Serial 7 subtraction gameplay, Tests attention and memory, Helps prevent cognitive decline, Measures subtraction speed, Randomized starting numbers

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

**In-app purchases:** none


### 초성퀴즈!

[App page](https://appshunter.io/ios/app/id6749453667)

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

**In-app purchases:** none


## Frequently asked questions

### Is Serial 7s free?

Serial 7s is free to download, with no in-app purchases.

### Is 초성퀴즈! free?

Pricing for 초성퀴즈! is not currently listed on the App Store.

### Do Serial 7s or 초성퀴즈! have ads?

Both Serial 7s and 초성퀴즈! show ads.

### Which is updated more often, Serial 7s or 초성퀴즈!?

Serial 7s ships an update every 5 months, and 초성퀴즈! every 3 weeks. Most recently, Serial 7s was updated on October 20, 2026 and 초성퀴즈! on October 25, 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.*