Comparison

Alarm Clock HD vs Atomic Clock PRO

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

Atomic Clock PRO

Get the most accurate time from an official atomic clock server. This app automatically detects your time zone and allows custom backgrounds. Easily switch between digital and analog clock displays with a swipe.

Highlights
  • Exact time from atomic clock
  • Automatic time zone recognition
  • Customizable background images
  • Digital and analog clock modes
  • Optional sound alerts
  • Color customization
Features
Read full description

Get accurate time on your iPhone and iPad by syncing with an official atomic clock time server. Download now for free! If you want exact time, a precise time reference, or an easy-to-read clock display, this app is designed for that. It automatically recognizes your time zone, lets you use one of your own photos as the background, and lets you switch between a digital display and a classic analog clock with a simple swipe. It is ideal as a personalized desk clock, a reliable travel companion, an everyday reference clock, or when you need exact time to set a mechanical watch accurately. Overview: - Accurate and precise time synced from an official atomic clock time server - Automatically recognizes your time zone and shows the current local time - Choose digital, analog, or combined analog and digital clock displays - Swipe to switch between clock displays - Resize the digital clock for a larger or smaller display - Includes time (hours, minutes, and seconds), date, and day of the week (optional) - Optional sound every second or every minute - Change clock and background colors - Use your own photos as background images - Choose atomic clock sync or your device's system clock - Option to keep the screen awake while the app is open - Works in portrait and landscape mode - For iPhone and iPad Helpful for: - A personalized desk clock at home or at work - Getting the correct local time while traveling - Setting a mechanical watch accurately - A clear reference clock when you want accurate, easy-to-read time PLEASE NOTE: You can switch between the analog and digital clock by swiping left or right across the clock. Disclaimer: Please note that whilst all reasonable care has been taken to make this application as accurate as possible we can not guarantee 100% accuracy. Standard Apple Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Alarm Clock HD4 screens
Atomic Clock PRO4 screens

Verdict

The call

The clearest difference is review sentiment: Atomic Clock PRO at 73% against Alarm Clock HD's 32%. Atomic Clock PRO also leads on rating (4.7 vs 4.5) and iOS requirement (15.6 vs 17.6). Alarm Clock HD's advantage is update cadence (fortnightly vs every 3 months) and ratings volume (104K vs 10K). On price, ads, in-app purchases and monetization model 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 11 in-app purchases, starting at $1.49 per month and Atomic Clock PRO sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Atomic Clock PRO holds the better App Store score, 4.7 against 4.5. That said, the two scores are not equally well evidenced: Alarm Clock HD has 104K ratings behind it against 10K, 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 73% of Atomic Clock PRO's.

UpkeepUpdate frequency

Alarm Clock HD ships an update fortnightly, Atomic Clock PRO every 3 months. Both last shipped on October 1, 2026.

Scorecard5 real differences · 5 level
Alarm Clock HD versus Atomic Clock PRO: the parameters behind the verdict, then further details
ParameterAlarm Clock HDAtomic Clock PRO
PriceFreeFree
Rating4.5 (104K ratings)4.7 (10K ratings) — better
Positive reviews32.1% of reviews72.7% of reviews — better
Number of ratings104K — better10K
Update frequencyFortnightly — betterEvery 3 months
AdsYesYes
In-app purchasesYesYes
MonetizationFreemiumFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.615.6 — better
Further details — not scored
Size230 MB6 MB
Age rating4+4+
DeveloperImpala StudiosBrachmann Online Marketing GmbH & Co. KG

Customer experience

Alarm Clock HD

All ratings104,102 ratings
Positive88.4%
Neutral4.7%
Negative6.9%
Written reviews910 reviews
Positive32.1%
Neutral8.2%
Negative59.7%

Atomic Clock PRO

All ratings10,111 ratings
Positive92.3%
Neutral3.5%
Negative4.2%
Written reviews421 reviews
Positive72.7%
Neutral6.2%
Negative21.1%

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

Atomic Clock PRO

From 10K App Store ratings

What we love

  • ⭐ Accurate time display
  • 📟 Useful for timing events
  • 🕰️ Helpful for setting other clocks
  • 🔍 Large, easy-to-read clock face

Room to improve

  • 💸 Subscription model for ad-free version
  • 📢 Excessive advertisements
  • 🔍 Small font for seconds display
  • 🔀 Difficulty in displaying both analog and digital clocks simultaneously

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

Atomic Clock PRO

Reported bugs

3 issues
  • Second hand occasionally runs in reverse
  • Digital clock display cuts off on some devices
  • Inconsistent behavior when switching between clock types

Requested features

3 requests
  • Customizable clock face options
  • Ability to set widget on home screen
  • Sync with system clock to automatically update time

In-app purchases

11 purchases

Alarm Clock HD

Subscriptions11
  • Premium member - 1 month$1.491 Month
  • Premium Features - Weekly$1.997 Days
  • Premium Features - Monthly3 Days trial$2.591 Month
Show 8 more
  • Upgrade to Premium Features$5.496 Months
  • Premium Yearly$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
  • Premium yearly3 Days trial$29.991 Year
2 purchases

Atomic Clock PRO

Subscriptions1
  • Premium$1.991 Month
One-time1
  • Remove Ads$5.99

Questions

Is Alarm Clock HD free?
Alarm Clock HD is free to download, with in-app purchases available.
Is Atomic Clock PRO free?
Atomic Clock PRO is free to download, with in-app purchases available.
Which has better reviews, Alarm Clock HD or Atomic Clock PRO?
Atomic Clock PRO is rated higher. Alarm Clock HD averages 4.5 out of 5 from 104K ratings, while Atomic Clock PRO averages 4.7 from 10K ratings.
Do Alarm Clock HD or Atomic Clock PRO have ads?
Both Alarm Clock HD and Atomic Clock PRO show ads.
Which is updated more often, Alarm Clock HD or Atomic Clock PRO?
Alarm Clock HD ships an update fortnightly, and Atomic Clock PRO every 3 months. Most recently, Alarm Clock HD was updated on October 1, 2026 and Atomic Clock PRO on October 1, 2026.

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