# CHALLNA vs 레트로 시계

The clearest difference is iOS requirement: 레트로 시계 at 13.0 against CHALLNA's 16.6. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

CHALLNA ships an update every 2 weeks, 레트로 시계 fortnightly. The most recent releases landed on October 12, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | CHALLNA | 레트로 시계 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Fortnightly |
| Monetization | Free | — |
| Size | 38 MB | 15 MB |
| Requires iOS | 16.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [RYNYUL](https://appshunter.io/developer/580531175) | [YOUNGJOO KIM](https://appshunter.io/developer/1851492729) |

## What reviewers say

### CHALLNA

[App page](https://appshunter.io/ios/app/challna-precise-server-clock/id6759583731)

This app helps you achieve precise timing for critical online events by displaying accurate server time, accounting for network latency. It offers one-touch presets for popular sites, countdown timers, and practice modes to improve your reaction speed for ticket sales, course registrations, and limited drops.

**Highlights:** Millisecond precision synchronization, One-touch server presets, Intuitive countdown timers, Click practice mode, Smart reminders and schedule registration, Direct site access, Dynamic Island support

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

**In-app purchases:** none


### 레트로 시계

[App page](https://appshunter.io/ios/app/id6760407197)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CHALLNA free?

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

### Is 레트로 시계 free?

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

### Do CHALLNA or 레트로 시계 have ads?

Neither CHALLNA nor 레트로 시계 shows ads.

### Which is updated more often, CHALLNA or 레트로 시계?

CHALLNA ships an update every 2 weeks, and 레트로 시계 fortnightly. Most recently, CHALLNA was updated on October 12, 2026 and 레트로 시계 on October 1, 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.*