# D vs バック計算

The clearest difference is ads: D at none against バック計算's shown. バック計算's advantage is update cadence (every 2 days vs fortnightly). On price, in-app purchases, device support and iOS requirement there is nothing between them.

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

D ships an update fortnightly, バック計算 every 2 days. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | D | バック計算 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Fortnightly | **Every 2 days** |
| Size | 75 MB | 32 MB |
| Requires iOS | **14.0** | 15.1 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 17+ | 12+ |
| Developer | [CLUTCH, INC. (Japan)](https://appshunter.io/developer/1525870754) | [Yujiro Sakai](https://appshunter.io/developer/1888860081) |

## What reviewers say

### D

[App page](https://appshunter.io/ios/app/d-manager/id6478853807)

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

**In-app purchases:** none


### バック計算

[App page](https://appshunter.io/ios/app/id6761976631)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is D free?

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

### Is バック計算 free?

バック計算 is free to download, with no in-app purchases.

### Do D or バック計算 have ads?

バック計算 shows ads; D does not.

### Which is updated more often, D or バック計算?

D ships an update fortnightly, and バック計算 every 2 days. Most recently, D was updated on November 8, 2026 and バック計算 on November 5, 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.*