# ただの電卓 vs Focus Mirror

The clearest difference is in-app purchases: ただの電卓 at none against Focus Mirror's 3. ただの電卓 also leads on ads (none vs shown) and iOS requirement (12.0 vs 17.0). Focus Mirror's advantage is update cadence (every 5 days vs fortnightly). On price and device support there is nothing between them.

Both are free to download. Focus Mirror sells 3 in-app purchases, starting at $0.99 per month. ただの電卓 asks for nothing beyond the download.

ただの電卓 ships an update fortnightly, Focus Mirror every 5 days. The most recent releases landed on October 12, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | ただの電卓 | Focus Mirror |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (3 ratings)](https://appshunter.io/ios/app/id1573909569/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 70.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Fortnightly | **Every 5 days** |
| Size | 14 MB | 8 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [HIROKI HORIGUCHI](https://appshunter.io/developer/1535451720) | [Takahiro Kimura](https://appshunter.io/developer/6775796488) |

## What reviewers say

### ただの電卓

[App page](https://appshunter.io/ios/app/id1573909569)

**Features:** macOS Compatibility

**In-app purchases:** none


### Focus Mirror

[App page](https://appshunter.io/ios/app/focus-mirror-study-timer/id6815692837)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads Monthly Plan | $0.99 | per month |
| Remove Ads Yearly Plan | $9.99 | per year |
| Remove Ads Lifetime | $39.99 | one-time |


## Frequently asked questions

### Is ただの電卓 free?

ただの電卓 is free to download, with no in-app purchases.

### Is Focus Mirror free?

Focus Mirror is free to download, with in-app purchases available.

### Do ただの電卓 or Focus Mirror have ads?

Focus Mirror shows ads; ただの電卓 does not.

### Which is updated more often, ただの電卓 or Focus Mirror?

ただの電卓 ships an update fortnightly, and Focus Mirror every 5 days. Most recently, ただの電卓 was updated on October 12, 2026 and Focus Mirror on October 9, 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.*