# NumbBrain vs Onsen Tamago

The clearest difference is in-app purchases: Onsen Tamago at none against NumbBrain's 3. Onsen Tamago also leads on update cadence (every 2 months vs every 4 months) and iOS requirement (15.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. NumbBrain sells 3 in-app purchases, starting at $0.99 per month. Onsen Tamago asks for nothing beyond the download.

NumbBrain ships an update every 4 months, Onsen Tamago every 2 months. Both last shipped on October 24, 2026.

## The numbers

| Metric | NumbBrain | Onsen Tamago |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/onsen-tamago-focus-timer/id6754348811/reviews)** |
| Number of ratings | — | **4** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | — | Free |
| Size | 14 MB | 229 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone | **iPhone, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [笛 姜](https://appshunter.io/developer/1561507357) | [Troubadour Game Studio LLC](https://appshunter.io/developer/1496572797) |

## What reviewers say

### NumbBrain

[App page](https://appshunter.io/ios/app/numbbrain-screen-time-control/id6751564003)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $0.99 | per month |
| Annual Premium | $2.99 | per year |
| Lifetime Premium | $5.99 | one-time |


### Onsen Tamago

[App page](https://appshunter.io/ios/app/onsen-tamago-focus-timer/id6754348811)

This app encourages focused work sessions by gamifying phone usage. Users engage in a virtual onsen experience that progresses as they stay off their device for set periods. It aims to improve concentration and well-being through mindful breaks.

**Highlights:** Gamified focus timer, Virtual onsen experience, Encourages phone-free time, Promotes well-being, Progressive onsen growth

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is NumbBrain free?

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

### Is Onsen Tamago free?

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

### Do NumbBrain or Onsen Tamago have ads?

Neither NumbBrain nor Onsen Tamago shows ads.

### Which is updated more often, NumbBrain or Onsen Tamago?

NumbBrain ships an update every 4 months, and Onsen Tamago every 2 months. Most recently, NumbBrain was updated on October 24, 2026 and Onsen Tamago on October 24, 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.*