# AtomicClock vs SkyAtlas

The clearest difference is review sentiment: AtomicClock at 84% against SkyAtlas's 40%. AtomicClock also leads on rating (4.8 vs 2.4) and ratings volume (5.6K vs 17). SkyAtlas's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. AtomicClock sells 1 one-off in-app purchase. SkyAtlas asks for nothing beyond the download.

AtomicClock holds the better App Store score, 4.8 against 2.4. That said, the two scores are not equally well evidenced: AtomicClock has 5.6K ratings behind it against 17, so its average is the more settled of the two. Written reviews point the same way: 84% of AtomicClock's written reviews are positive against 40% of SkyAtlas's.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on October 19, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | AtomicClock | SkyAtlas |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (5.6K ratings)](https://appshunter.io/ios/app/atomicclock-ntp-time/id1402993049/reviews)** | [2.4 (17 ratings)](https://appshunter.io/ios/app/skyatlas/id1616449238/reviews) |
| Number of ratings | **5.6K** | 17 |
| Positive reviews | **84.3% of reviews** | 40.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Monthly | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 17 MB | 911 MB |
| Requires iOS | 17.4 | **11.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Timo Partl](https://appshunter.io/developer/1387413672) | [SuZhou ZWO Co., Ltd](https://appshunter.io/developer/1367782033) |

## What reviewers say

### AtomicClock

[App page](https://appshunter.io/ios/app/atomicclock-ntp-time/id1402993049)

This app displays the exact current time synchronized with NTP servers, offering a customizable clock view for precise time checks. It's ideal for setting watches, verifying timestamps, or comparing local and network time.

**Highlights:** Precise time from NTP servers, Customizable clock faces, Select or add time servers, Local and UTC views, 12/24 hour modes, Customizable time format, Acoustic ticking

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Pro Version | $6.99 | one-time |

**What reviewers like**

- 🚀 Accurate time
- 👍 Highly customizable
- 🚀 Precise to the second
- 👍 Easy to use
- 👍 Helpful for setting watches

**What reviewers complain about**

- 🐛 Server connection issues
- 🔍 Limited time zone options
- 💰 Ads diminish clock view
- 🔍 Lacks some advanced features
- 🔍 Redundant for some users

**Reported bugs**

- Crashes on certain iOS versions
- Occasional freezing of hands
- Countdown timer sound not working

**Requested features**

- Add GMT/dual time display
- Implement widget support
- Add different second hand sounds
- Allow setting background color to match watch
- Include alarm/timer functionality


### SkyAtlas

[App page](https://appshunter.io/ios/app/skyatlas/id1616449238)

Explore the night sky with a digital atlas and control your telescope mount. Plan astrophotography compositions with simulated camera fields of view and track celestial objects in real-time. Features one-click GoTo and mode switching for an enhanced stargazing experience.

**Highlights:** Digital sky atlas exploration, Telescope mount control (ZWO ASI), Simulated camera field of view, Real-time telescope pointing display, One-click GoTo functionality, Object tracking, EQ and AltAz mode switching

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

**In-app purchases:** none


## Frequently asked questions

### Is AtomicClock free?

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

### Is SkyAtlas free?

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

### Which has better reviews, AtomicClock or SkyAtlas?

AtomicClock is rated higher. AtomicClock averages 4.8 out of 5 from 5.6K ratings, while SkyAtlas averages 2.4 from 17 ratings.

### Do AtomicClock or SkyAtlas have ads?

AtomicClock shows ads; SkyAtlas does not.

### Which is updated more often, AtomicClock or SkyAtlas?

AtomicClock ships an update monthly, and SkyAtlas monthly. Most recently, AtomicClock was updated on October 19, 2026 and SkyAtlas on October 10, 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.*