# 暗算Blitz vs Double Digits

The clearest difference is in-app purchases: Double Digits at none against 暗算Blitz's 1. Double Digits also leads on ads (none vs shown) and iOS requirement (15.1 vs 17.6). 暗算Blitz's advantage is update cadence (daily vs every 5 weeks). On price and device support there is nothing between them.

Both are free to download. 暗算Blitz sells 1 one-off in-app purchase. Double Digits asks for nothing beyond the download.

暗算Blitz ships an update daily, Double Digits every 5 weeks. The most recent releases landed on October 3, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | 暗算Blitz | Double Digits |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Daily** | Every 5 weeks |
| Size | 54 MB | 28 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Toshihide KAWAI](https://appshunter.io/developer/1598098272) | [shota shimogama](https://appshunter.io/developer/6796290145) |

## What reviewers say

### 暗算Blitz

[App page](https://appshunter.io/ios/app/blitz/id6741730652)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プレミアム・ユーザー | $14.99 | one-time |


### Double Digits

[App page](https://appshunter.io/ios/app/double-digits-mental-math/id6796290143)

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

**In-app purchases:** none


## Frequently asked questions

### Is 暗算Blitz free?

暗算Blitz is free to download, with in-app purchases available.

### Is Double Digits free?

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

### Do 暗算Blitz or Double Digits have ads?

暗算Blitz shows ads; Double Digits does not.

### Which is updated more often, 暗算Blitz or Double Digits?

暗算Blitz ships an update daily, and Double Digits every 5 weeks. Most recently, 暗算Blitz was updated on October 3, 2026 and Double Digits on October 11, 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.*