Comparison

Alarm Clock HD vs AtomicClock

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Alarm Clock HD

Wake up gently with your favorite music or sounds using this advanced alarm clock. It offers customizable nightstand displays, sleep tracking, and a sleep timer to help you unwind. Enjoy features like local weather and an instant flashlight, with an option to go ad-free via subscription.

Highlights
  • Unlimited alarms with Apple Music or custom sounds
  • Sleep tracking
  • Customizable nightstand display
  • Sleep timer
  • Local weather information
  • Instant flashlight
  • Screen saver for OLED displays
Features
Read full description

Sleep better and start the day with your favorite tunes. Are you curious to see how much you slept? Then, track your sleep in the app. Alarm Clock HD is the app to help you enjoy restful sleep and wake up worry-free. How Alarm Clock HD helps you sleep better: • Unlimited Alarms: Apple Music or Alarm Sounds • Customize Nightstand display colors • Sleep Timer • Local Weather Information • Instant Flashlight - shake the device • Full watchOS 2 support • Screen Saver - for devices with OLED display WAKE UP ON TIME: Proper Alarm Settings • Keep the app open and running always to have your alarm go off and play the sounds you’ve set for ‘Music'. When your app is open, you can use the volume slider within the app. When the app is in the background, use the device volume to set your volume. • Make sure your battery is charged and have your notifications turned on before you go to sleep, when the battery level goes below 30% it might not sound. This is due to prevent the device from dying and the alarm not going off. • Keep your Apple Music available on your device The music you can select consists of everything you have available on your ‘Apple Music' app on your device. If the music is saved on your iCloud, and not on the device itself, it won’t be available. NEVER MISS AN ALARM When you close the app and do not have it running in the background, the alarm will use the device volume instead and play the notification sound system. The app will close itself automatically after 10 hours of inactivity. This is due to prevent the device from dying and the alarm not going off. When your device is muted, set to ‘Do Not Disturb’, or your device volume is set to 0, the alarm won’t play properly. It will still show the notification without any sound. This is due to Apple’s restrictions as we are unable to access the app settings when the app is closed, only when it’s open or running in the background. SUBSCRIPTION IN ALARM CLOCK HD Upgrade to a Premium Membership and receive the following ongoing value: • Ad-Free • News & X feeds (Twitter) • Premium Customer Support Terms & Conditions: https://impalastudios.com/terms Privacy Policy: https://impalastudios.com/privacy >> WE LOVE FEEDBACK As always, we appreciate your feedback. Please email us at support@impalastudios.com with any suggestions or questions, our support team is ready and happy to help. WAKE UP YOUR WAY, EVERY DAY

About

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.

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
Read full description

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

Alarm Clock HD4 screens
AtomicClock4 screens

Verdict

The call

The clearest difference is review sentiment: AtomicClock at 85% against Alarm Clock HD's 32%. AtomicClock also leads on rating (4.8 vs 4.5) and iOS requirement (15.0 vs 17.6). Alarm Clock HD's advantage is ratings volume (104K vs 5.5K). On price, update cadence, ads and in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Alarm Clock HD sells 10 in-app purchases, starting at $1.49 per month and AtomicClock sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

AtomicClock holds the better App Store score, 4.8 against 4.5. That said, the two scores are not equally well evidenced: Alarm Clock HD has 104K ratings behind it against 5.5K, so its average is the more settled of the two. Written reviews point the same way: 32% of Alarm Clock HD's written reviews are positive against 85% of AtomicClock's.

UpkeepUpdate frequency

Alarm Clock HD ships an update fortnightly, AtomicClock every 3 weeks. Both last shipped on September 24, 2026.

Scorecard4 real differences · 6 level
Alarm Clock HD versus AtomicClock: the parameters behind the verdict, then further details
ParameterAlarm Clock HDAtomicClock
PriceFreeFree
Rating4.5 (104K ratings)4.8 (5.5K ratings) — better
Positive reviews32.0% of reviews84.5% of reviews — better
Number of ratings104K — better5.5K
Update frequencyFortnightly — betterEvery 3 weeks
AdsYesYes
In-app purchasesYesYes
MonetizationFreemiumFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.615.0 — better
Further details — not scored
Size230 MB17 MB
Age rating4+4+
DeveloperImpala StudiosTimo Partl

Customer experience

Alarm Clock HD

All ratings104,102 ratings
Positive88.4%
Neutral4.7%
Negative6.9%
Written reviews908 reviews
Positive32.0%
Neutral8.3%
Negative59.7%

AtomicClock

All ratings5,539 ratings
Positive96.5%
Neutral1.8%
Negative1.8%
Written reviews239 reviews
Positive84.5%
Neutral3.3%
Negative12.1%

User reviews

Alarm Clock HD

From 104K App Store ratings

What we love

  • 🚀 Reliable alarm clock
  • 🎨 Customizable colors
  • 🔊 Ability to use music as alarm
  • 💤 Gradual volume increase

Room to improve

  • 🐛 Alarm not going off
  • 🔍 Difficulty seeing small buttons/text
  • 💸 Subscription model for ad-free version
  • 🔋 High battery consumption
  • 🔇 Alarm muting phone volume

AtomicClock

From 5.5K App Store ratings

What 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

Alarm Clock HD

Reported bugs

4 issues
  • Alarm randomly snoozing itself
  • Alarm not working when phone is muted
  • Alarm sound not playing
  • Alarm screen freezing/crashing

Requested features

4 requests
  • 24-hour clock option
  • More alarm sounds/tones
  • Ability to use own music files
  • Do not disturb mode

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

10 purchases

Alarm Clock HD

Subscriptions10
  • Premium member - 1 month$1.491 Month
  • Premium Features - Weekly$1.997 Days
  • Premium Features - Monthly3 Days trial$2.591 Month
Show 7 more
  • Upgrade to Premium Features$5.496 Months
  • Premium Yearly3 Days trial$9.991 Year
  • Premium Yearly3 Days trial$11.991 Year
  • Upgrade Your Alarm Clock3 Days trial$14.991 Year
  • Premium yearly$19.991 Year
  • Premium yearly3 Days trial$19.991 Year
  • Premium yearly3 Days trial$24.991 Year
1 purchases

AtomicClock

One-time1
  • Lifetime Pro Version$6.99

Questions

Is Alarm Clock HD free?
Alarm Clock HD is free to download, with in-app purchases available.
Is AtomicClock free?
AtomicClock is free to download, with in-app purchases available.
Which has better reviews, Alarm Clock HD or AtomicClock?
AtomicClock is rated higher. Alarm Clock HD averages 4.5 out of 5 from 104K ratings, while AtomicClock averages 4.8 from 5.5K ratings.
Do Alarm Clock HD or AtomicClock have ads?
Both Alarm Clock HD and AtomicClock show ads.
Which is updated more often, Alarm Clock HD or AtomicClock?
Alarm Clock HD ships an update fortnightly, and AtomicClock every 3 weeks. Most recently, Alarm Clock HD was updated on September 24, 2026 and AtomicClock on September 24, 2026.

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