# Debt Clock vs 深海自習室

The clearest difference is iOS requirement: Debt Clock at 13.0 against 深海自習室's 18.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Debt Clock sells 2 in-app purchases, starting at $1.99 per month and 深海自習室 sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly every 2 days. The most recent releases landed on October 18, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Debt Clock | 深海自習室 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 2 days | Every 2 days |
| Size | 25 MB | 7 MB |
| Requires iOS | **13.0** | 18.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Kanta Osumi](https://appshunter.io/developer/1872595837) | [KAZUSA NAOI](https://appshunter.io/developer/1863197671) |

## What reviewers say

### Debt Clock

[App page](https://appshunter.io/ios/app/debt-clock/id6758671250)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プレミアムプラン（月額） | $1.99 | per month |
| プレミアムプラン（年額） | $14.99 | per year |


### 深海自習室

[App page](https://appshunter.io/ios/app/id6800208005)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 装備を新しくする | $4.99 | one-time |


## Frequently asked questions

### Is Debt Clock free?

Debt Clock is free to download, with in-app purchases available.

### Is 深海自習室 free?

深海自習室 is free to download, with in-app purchases available.

### Do Debt Clock or 深海自習室 have ads?

Both Debt Clock and 深海自習室 show ads.

### Which is updated more often, Debt Clock or 深海自習室?

Debt Clock ships an update every 2 days, and 深海自習室 every 2 days. Most recently, Debt Clock was updated on October 18, 2026 and 深海自習室 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.*