# Missing Num vs 21日で学ぶ歎異抄

The clearest difference is ads: 21日で学ぶ歎異抄 at none against Missing Num's shown. 21日で学ぶ歎異抄 also leads on update cadence (every 4 days vs every 11 months). Missing Num's advantage is iOS requirement (15.6 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.

Missing Num ships an update every 11 months, 21日で学ぶ歎異抄 every 4 days. The most recent releases landed on September 30, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Missing Num | 21日で学ぶ歎異抄 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 11 months | **Every 4 days** |
| Size | 8 MB | 6 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [Yoshihide Matsumoto](https://appshunter.io/developer/6788531770) |

## What reviewers say

### Missing Num

[App page](https://appshunter.io/ios/app/missing-num/id868026877)

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

**In-app purchases:** none


### 21日で学ぶ歎異抄

[App page](https://appshunter.io/ios/app/21/id6788531768)

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

**In-app purchases:** none


## Frequently asked questions

### Is Missing Num free?

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

### Is 21日で学ぶ歎異抄 free?

21日で学ぶ歎異抄 is free to download, with no in-app purchases.

### Do Missing Num or 21日で学ぶ歎異抄 have ads?

Missing Num shows ads; 21日で学ぶ歎異抄 does not.

### Which is updated more often, Missing Num or 21日で学ぶ歎異抄?

Missing Num ships an update every 11 months, and 21日で学ぶ歎異抄 every 4 days. Most recently, Missing Num was updated on September 30, 2026 and 21日で学ぶ歎異抄 on September 20, 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.*