# Fast Clock vs TT Clock

The clearest difference is update cadence: Fast Clock at every 2 days against TT Clock's every 3 weeks. TT Clock's advantage is iOS requirement (13.0 vs 15.6). 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.

Fast Clock ships an update every 2 days, TT Clock every 3 weeks. The most recent releases landed on September 20, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Fast Clock | TT 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 | No |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 3 weeks |
| Monetization | Free | — |
| Size | 5 MB | 29 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kevin Snow](https://appshunter.io/developer/305581830) | [Shenzhen PROS Electronics Co.,Ltd](https://appshunter.io/developer/1798637623) |

## 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


### TT Clock

[App page](https://appshunter.io/ios/app/tt-clock/id6748670158)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Fast Clock free?

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

### Is TT Clock free?

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

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

Neither Fast Clock nor TT Clock shows ads.

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

Fast Clock ships an update every 2 days, and TT Clock every 3 weeks. Most recently, Fast Clock was updated on September 20, 2026 and TT Clock on October 8, 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.*