# World Time Shifter Clock vs Must Ring

The clearest difference is in-app purchases: World Time Shifter Clock at none against Must Ring's 1. World Time Shifter Clock also leads on iOS requirement (18.0 vs 26.1). Must Ring's advantage is ads (none vs shown). On price, update cadence and device support there is nothing between them.

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

World Time Shifter Clock ships an update every 3 weeks, Must Ring fortnightly. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | World Time Shifter Clock | Must Ring |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (98 ratings)](https://appshunter.io/ios/app/world-time-shifter-clock/id1499246199/reviews)** | — |
| Number of ratings | **98** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | **Fortnightly** |
| Monetization | Ad-supported | — |
| Size | 23 MB | 12 MB |
| Requires iOS | **18.0** | 26.1 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [David Richmond](https://appshunter.io/developer/329944573) | [大胜 纪](https://appshunter.io/developer/320513564) |

## What reviewers say

### World Time Shifter Clock

[App page](https://appshunter.io/ios/app/world-time-shifter-clock/id1499246199)

This app helps you manage time across different time zones for global coordination. Easily plan meetings, stay connected with loved ones, and track events worldwide. Its intuitive display and time-shifting feature make it simple to understand and use.

**Highlights:** Intuitive world clock display, Time shifting for time zone comparison, Meeting scheduling across time zones, Travel time forecasting, Event reminders and notifications

**Features:** macOS Compatibility

**In-app purchases:** none


### Must Ring

[App page](https://appshunter.io/ios/app/must-ring/id6812251518)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Must Ring Unlock | $14.99 | one-time |


## Frequently asked questions

### Is World Time Shifter Clock free?

World Time Shifter Clock is free to download, with no in-app purchases.

### Is Must Ring free?

Must Ring is free to download, with in-app purchases available.

### Do World Time Shifter Clock or Must Ring have ads?

World Time Shifter Clock shows ads; Must Ring does not.

### Which is updated more often, World Time Shifter Clock or Must Ring?

World Time Shifter Clock ships an update every 3 weeks, and Must Ring fortnightly. Most recently, World Time Shifter Clock was updated on November 3, 2026 and Must Ring on October 31, 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.*