# Ukenummer vs Castella

The clearest difference is update cadence: Castella at weekly against Ukenummer's every 31 months. Castella also leads on iOS requirement (15.6 vs 18.0). On price, ads, 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.

Ukenummer ships an update every 31 months, Castella weekly. The most recent releases landed on October 10, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Ukenummer | Castella |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 31 months | **Weekly** |
| Size | 3 MB | 9 MB |
| Requires iOS | 18.0 | **15.6** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Ibrahim Qraiqe](https://appshunter.io/developer/318538483) | [Serdar Percin](https://appshunter.io/developer/1143186597) |

## What reviewers say

### Ukenummer

[App page](https://appshunter.io/ios/app/ukenummer-week-number/id668805988)

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

**In-app purchases:** none


### Castella

[App page](https://appshunter.io/ios/app/castella/id6749802163)

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

**In-app purchases:** none


## Frequently asked questions

### Is Ukenummer free?

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

### Is Castella free?

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

### Do Ukenummer or Castella have ads?

Neither Ukenummer nor Castella shows ads.

### Which is updated more often, Ukenummer or Castella?

Ukenummer ships an update every 31 months, and Castella weekly. Most recently, Ukenummer was updated on October 10, 2026 and Castella on October 11, 2026.

---

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