Dark Sky Meter vs AtomicClock
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Dark Sky Meter
This application utilizes your device's camera to measure the brightness of the night sky. The collected data can be optionally shared with scientific researchers worldwide.
- Measures sky brightness
- Uses device camera
- Optional data sharing
- Contributes to scientific research
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The Dark Sky Meter app measures the sky brightness using the camera and shares it (optionally) with scientists around the globe.
AtomicClock
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.
- 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
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Check precise NTP reference time at a glance. AtomicClock helps you set watches, wall clocks, cameras, and other devices, compare local time with UTC, and follow moments when every second matters. Clear analog and digital time AtomicClock displays current time from NTP servers that reference atomic clocks. Choose a predefined server or add your own, then view local or UTC time in a clean analog or digital clock. Customize your reference clock • Switch between 12-hour and 24-hour time • Customize the time format • Choose from multiple clock faces and hands • Use a smooth, fluid second hand • Add acoustic ticking or the Greenwich Time Signal • Tap the screen to hide information and controls, freeze the display, or mute ticking Details for precise time checks View technical NTP information, including round-trip time and server stratum. Whether you are checking a timestamp, preparing a camera, aligning a wall clock, or setting a watch by hand, the seconds remain clear and easy to follow. AtomicClock is free to use. AtomicClock Pro is available as a one-time purchase with no subscription. It unlocks your preferred clock face, hands, and font, removes ads, and includes upcoming Pro features. AtomicClock displays NTP reference time for comparison and does not change your device’s system time. Results can vary with the selected server, network conditions, and device behavior.
Screenshots
Verdict
The clearest difference is price: AtomicClock at Free against Dark Sky Meter's $1.99. AtomicClock also leads on review sentiment (84% vs 40%) and rating (4.8 vs 3.8). Dark Sky Meter's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
AtomicClock is free to download; Dark Sky Meter costs $1.99 up front. AtomicClock sells 1 one-off in-app purchase. Dark Sky Meter asks for nothing beyond the download.
AtomicClock holds the better App Store score, 4.8 against 3.8. That said, the two scores are not equally well evidenced: AtomicClock has 5.6K ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 40% of Dark Sky Meter's written reviews are positive against 84% of AtomicClock's.
Dark Sky Meter ships an update every 3 months, AtomicClock monthly. Both last shipped on November 13, 2026.
| Parameter | Dark Sky Meter | AtomicClock |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 3.8 (6 ratings) | 4.8 (5.6K ratings) — better |
| Positive reviews | 40.4% of reviews | 84.3% of reviews — better |
| Number of ratings | 6 | 5.6K — better |
| Update frequency | Every 3 months | Monthly — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Best chart rank | #71 — better | — |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 15.6 — better | 17.4 |
| Further details — not scored | ||
| Size | 4 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | DDQ | Timo Partl |
Customer experience
Dark Sky Meter
AtomicClock
User reviews
Dark Sky Meter
From 6 App Store ratingsWhat we love
- 💡 Great idea for dark sky measurement
- 👍 Easy to use interface
- 💰 Good value for price
- 🔭 Useful for astronomers
- 🗺️ Contributes to dark sky mapping
Room to improve
- 📉 Inaccurate readings compared to SQM meters
- 🚫 "Too dark for device" error frequently
- 📱 Inconsistent performance on newer iPhones
- 💻 Website/support links are unhelpful
- ❓ Lacks clear instructions
AtomicClock
From 5.6K App Store ratingsWhat we love
- 🚀 Accurate time
- 👍 Highly customizable
- 🚀 Precise to the second
- 👍 Easy to use
- 👍 Helpful for setting watches
Room to improve
- 🐛 Server connection issues
- 🔍 Limited time zone options
- 💰 Ads diminish clock view
- 🔍 Lacks some advanced features
- 🔍 Redundant for some users
Bugs and requests
Dark Sky Meter
Reported bugs
9 issues- App crashes frequently
- "Too dark for device" error persists
- Inaccurate measurements
- History of measurements lost after updates
- App does not start after update
Show 4 moreShow fewer
- Cloud button causes crash
- Weather data not functioning
- Camera area display is too small
- Network operations not working
Requested features
8 requests- Option to use front-facing camera
- Automatic dark and light measurements
- Local time display instead of UTC
- Calibration function to add offset
- List of observations to be restored
Show 3 moreShow fewer
- Include cloud cover data in map view
- Store own measurements for documentation
- Information on Seeing and Transparency scales
AtomicClock
Reported bugs
3 issues- Crashes on certain iOS versions
- Occasional freezing of hands
- Countdown timer sound not working
Requested features
5 requests- Add GMT/dual time display
- Implement widget support
- Add different second hand sounds
- Allow setting background color to match watch
- Include alarm/timer functionality
In-app purchases
Dark Sky Meter
No in-app purchases
AtomicClock
- Lifetime Pro Version$6.99









