# PenFlow vs さんすう水族館

The clearest difference is in-app purchases: PenFlow at none against さんすう水族館's 6. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. さんすう水族館 sells 6 one-off in-app purchases. PenFlow asks for nothing beyond the download.

PenFlow ships an update every 10 days, さんすう水族館 weekly. The most recent releases landed on October 7, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | PenFlow | さんすう水族館 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | **Weekly** |
| Size | 5 MB | 22 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SANWA Inc.](https://appshunter.io/developer/1878028373) | [Kosuke Mawatari](https://appshunter.io/developer/1489564137) |

## What reviewers say

### PenFlow

[App page](https://appshunter.io/ios/app/penflow/id6761091973)

**Features:** macOS Compatibility

**In-app purchases:** none


### さんすう水族館

[App page](https://appshunter.io/ios/app/id6796571918)

**Features:** macOS Compatibility

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 3けたのかず ぜんぶあそぶ | $0.99 | one-time |
| かずをかぞえる1〜10まで ぜんぶあそぶ | $0.99 | one-time |
| かずをかぞえる10〜20まで ぜんぶあそぶ | $0.99 | one-time |
| 1けたのけいさん ぜんぶあそぶ | $0.99 | one-time |
| とけい・じこくとじかん ぜんぶあそぶ | $0.99 | one-time |
| おかいもの・おつり100円と200円 ぜんぶあそぶ | $0.99 | one-time |


## Frequently asked questions

### Is PenFlow free?

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

### Is さんすう水族館 free?

さんすう水族館 is free to download, with in-app purchases available.

### Do PenFlow or さんすう水族館 have ads?

Neither PenFlow nor さんすう水族館 shows ads.

### Which is updated more often, PenFlow or さんすう水族館?

PenFlow ships an update every 10 days, and さんすう水族館 weekly. Most recently, PenFlow was updated on October 7, 2026 and さんすう水族館 on October 8, 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.*