# - Timekeeper - vs Müller

The clearest difference is ads: - Timekeeper - at none against Müller's shown. - Timekeeper - also leads on update cadence (fortnightly vs every 9 months). Müller's advantage is iOS requirement (12.0 vs 15.0). 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.

- Timekeeper - ships an update fortnightly, Müller every 9 months. The most recent releases landed on October 25, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | - Timekeeper - | Müller |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Fortnightly** | Every 9 months |
| Size | 1 MB | 30 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Minshun Yang](https://appshunter.io/developer/1489568228) | [SOCIA LABO, K.K.](https://appshunter.io/developer/1688326248) |

## What reviewers say

### - Timekeeper -

[App page](https://appshunter.io/ios/app/timekeeper/id1599214125)

**Features:** macOS Compatibility

**In-app purchases:** none


### Müller

[App page](https://appshunter.io/ios/app/muller-lyer-illusion-app/id6450165949)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is - Timekeeper - free?

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

### Is Müller free?

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

### Do - Timekeeper - or Müller have ads?

Müller shows ads; - Timekeeper - does not.

### Which is updated more often, - Timekeeper - or Müller?

- Timekeeper - ships an update fortnightly, and Müller every 9 months. Most recently, - Timekeeper - was updated on October 25, 2026 and Müller on October 27, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*