# Fast Clock vs World Clock

The clearest difference is in-app purchases: Fast Clock at none against World Clock's 1. Fast Clock also leads on update cadence (every 2 days vs every 5 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. World Clock sells 1 one-off in-app purchase. Fast Clock asks for nothing beyond the download.

Fast Clock ships an update every 2 days, World Clock every 5 weeks. The most recent releases landed on September 20, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Fast Clock | World Clock |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.8 (5 ratings)](https://appshunter.io/ios/app/fast-clock/id6448879724/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 25.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 5 weeks |
| Monetization | Free | — |
| Size | 5 MB | 41 MB |
| Requires iOS | 15.6 | **15.1** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kevin Snow](https://appshunter.io/developer/305581830) | [Tomash Sugint](https://appshunter.io/developer/1896504334) |

## What reviewers say

### Fast Clock

[App page](https://appshunter.io/ios/app/fast-clock/id6448879724)

This application simulates a fast clock for model railroads. It allows for custom logos and maps, and can synchronize with external systems like JMRI or use real-time.

**Highlights:** Model railroad fast clock simulation, Custom logo support, Custom map integration, JMRI time synchronization, Real-time clock option

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

**In-app purchases:** none


### World Clock

[App page](https://appshunter.io/ios/app/world-clock-timeshift/id6768507524)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| TimeShift Pro | $3.99 | one-time |


## Frequently asked questions

### Is Fast Clock free?

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

### Is World Clock free?

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

### Do Fast Clock or World Clock have ads?

Neither Fast Clock nor World Clock shows ads.

### Which is updated more often, Fast Clock or World Clock?

Fast Clock ships an update every 2 days, and World Clock every 5 weeks. Most recently, Fast Clock was updated on September 20, 2026 and World Clock on September 16, 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.*