# isPrime? vs Eternal Clock

The clearest difference is update cadence: Eternal Clock at weekly against isPrime?'s every 16 months. Eternal Clock also leads on iOS requirement (12.0 vs 15.0). 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.

isPrime? ships an update every 16 months, Eternal Clock weekly. The most recent releases landed on October 25, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | isPrime? | Eternal Clock |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/eternal-clock/id6752602424/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 16 months | **Weekly** |
| Monetization | — | Free |
| Size | 4 MB | 23 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Omer Faruk Mesebuken](https://appshunter.io/developer/1655501999) | [Daehyeon Shin](https://appshunter.io/developer/1698890567) |

## What reviewers say

### isPrime?

[App page](https://appshunter.io/ios/app/isprime/id6478832061)

**Features:** macOS Compatibility

**In-app purchases:** none


### Eternal Clock

[App page](https://appshunter.io/ios/app/eternal-clock/id6752602424)

A minimalist digital clock that displays the time with no distractions. It offers a clean interface with subtle visual cues like a sun, moon, or mealtime hints, all without ads, data collection, or notifications.

**Highlights:** Ad-free experience, No data collection, No push notifications, Minimalist interface, Subtle visual cues (sun, moon, food), No settings or permissions required

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

**In-app purchases:** none


## Frequently asked questions

### Is isPrime? free?

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

### Is Eternal Clock free?

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

### Do isPrime? or Eternal Clock have ads?

Neither isPrime? nor Eternal Clock shows ads.

### Which is updated more often, isPrime? or Eternal Clock?

isPrime? ships an update every 16 months, and Eternal Clock weekly. Most recently, isPrime? was updated on October 25, 2026 and Eternal Clock on October 21, 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.*