# Serial 7s vs Bubble Boom

The clearest difference is ads: Bubble Boom at none against Serial 7s's shown. Serial 7s's advantage is iOS requirement (15.0 vs 17.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | Serial 7s | Bubble Boom |
| --- | --- | --- |
| Price | Free | 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 | **No** |
| Update frequency | Every 5 months | — |
| Monetization | Ad-supported | — |
| Size | 42 MB | 1 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 9+ | 4+ |
| Developer | [HFX Lab](https://appshunter.io/developer/1139262927) | [Vladimir Zhizhin](https://appshunter.io/developer/1382250646) |

## 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


### Bubble Boom

[App page](https://appshunter.io/ios/app/bubble-boom/id6504180019)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Serial 7s free?

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

### Is Bubble Boom free?

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

### Do Serial 7s or Bubble Boom have ads?

Serial 7s shows ads; Bubble Boom does not.

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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.*