# Atomic Exact Time vs Reaction Time Test

The clearest difference is in-app purchases: Reaction Time Test at none against Atomic Exact Time's 3. Reaction Time Test also leads on ads (none vs shown) and update cadence (every 8 days vs every 5 weeks). Atomic Exact Time's advantage is device support (4 vs 2). On price and iOS requirement there is nothing between them.

Both are free to download. Atomic Exact Time sells 3 in-app purchases, starting at $2.99 per month. Reaction Time Test asks for nothing beyond the download.

Atomic Exact Time ships an update every 5 weeks, Reaction Time Test every 8 days. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Atomic Exact Time | Reaction Time Test |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/atomic-exact-time/id6797418012/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 5 weeks | **Every 8 days** |
| Monetization | Free with in-app purchases | — |
| Size | 56 MB | 5 MB |
| Requires iOS | **16.4** | 17.0 |
| Devices | **iPhone, iPad, Mac, Apple TV** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SUPER KIM KIMYA VE TEKSTIL SANAYI TICARET LIMITED SIRKETI](https://appshunter.io/developer/1896542696) | [Jinwan Kim](https://appshunter.io/developer/1446513824) |

## What reviewers say

### Atomic Exact Time

[App page](https://appshunter.io/ios/app/atomic-exact-time/id6797418012)

This app precisely calibrates your device's clock against internet time sources, accounting for network delays. It offers a full-screen display with millisecond accuracy, detailed reports on clock deviation, and a precision alarm. Ideal for professionals and enthusiasts requiring exact timing.

**Highlights:** Millisecond accurate clock display, Device offset status, Network latency and drift reports, Precision alarm, Timecode and markers, Widgets, Multiple clock themes

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Atomic Exact Time Pro | $2.99 | per month |
| Pro Yearly | $19.99 | per year |
| Atomic Exact Time Pro | $2.99 | one-time |


### Reaction Time Test

[App page](https://appshunter.io/ios/app/reaction-time-test-millis/id6805464656)

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

**In-app purchases:** none


## Frequently asked questions

### Is Atomic Exact Time free?

Atomic Exact Time is free to download, with in-app purchases available.

### Is Reaction Time Test free?

Reaction Time Test is free to download, with no in-app purchases.

### Do Atomic Exact Time or Reaction Time Test have ads?

Atomic Exact Time shows ads; Reaction Time Test does not.

### Which is updated more often, Atomic Exact Time or Reaction Time Test?

Atomic Exact Time ships an update every 5 weeks, and Reaction Time Test every 8 days. Most recently, Atomic Exact Time was updated on November 6, 2026 and Reaction Time Test 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.*