# バック計算 vs PatronBook

The clearest difference is ads: PatronBook at none against バック計算's shown. バック計算's advantage is update cadence (every 2 days vs every 3 weeks) and iOS requirement (15.1 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.

バック計算 ships an update every 2 days, PatronBook every 3 weeks. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | バック計算 | PatronBook |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 2 days** | Every 3 weeks |
| Monetization | — | Freemium |
| Size | 32 MB | 14 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 12+ | 17+ |
| Developer | [Yujiro Sakai](https://appshunter.io/developer/1888860081) | [Mitsuhiro Hashimoto](https://appshunter.io/developer/509482512) |

## What reviewers say

### バック計算

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

**Features:** macOS Compatibility

**In-app purchases:** none


### PatronBook

[App page](https://appshunter.io/ios/app/patronbook-client-notes-crm/id6786539042)

Manage client notes, visits, and sales for hospitality professionals. Track guest preferences, log interactions, and view sales performance. Receive birthday reminders and secure your data locally with app lock.

**Highlights:** Easy guest notes with photos and tags, Quick visit logging, Sales tracking and goal progress, Birthday reminders, Local data storage, Face ID/passcode app lock, Guest rankings (Premium)

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

**In-app purchases:** none


## Frequently asked questions

### Is バック計算 free?

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

### Is PatronBook free?

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

### Do バック計算 or PatronBook have ads?

バック計算 shows ads; PatronBook does not.

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

バック計算 ships an update every 2 days, and PatronBook every 3 weeks. Most recently, バック計算 was updated on November 5, 2026 and PatronBook on October 31, 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.*