Big Clock HD vs Atomic Clock PRO
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Big Clock HD
This app displays a large, easily readable digital clock on your device, perfect for viewing from afar. It supports all iOS locales and can prevent your device from auto-locking while the clock is displayed. Additional features include seconds display and widgets.
- Large, readable date and time display
- Supports all iOS locales
- Prevents auto-locking
- Optional seconds display
- Widgets
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Big Clock HD displays a big digital clock on your iPhone / iPad that's readable even from a distance. All iOS locales are supported, change them in the settings for the app. If there's no big clock on the wall - now there's one in your pocket or in your iPad Dock! FEATURES - Big, readable display of date and time - Localized in all languages the iPhone/iPad supports - Prevents phone / iPad from auto-locking while displaying the time - Add seconds display via the Settings App - Widgets
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.
- Exact time from atomic clock
- Automatic time zone recognition
- Customizable background images
- Digital and analog clock modes
- Optional sound alerts
- Color customization
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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
Verdict
The clearest difference is price: Atomic Clock PRO at Free against Big Clock HD's $0.49. Atomic Clock PRO also leads on rating (4.7 vs 3.0) and update cadence (every 3 months vs every 29 months). Big Clock HD's advantage is in-app purchases (none vs 2) and ads (none vs shown). On iOS requirement 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
Atomic Clock PRO is free to download; Big Clock HD costs $0.49 up front. Atomic Clock PRO sells 2 in-app purchases, starting at $1.99 per month. Big Clock HD asks for nothing beyond the download.
Atomic Clock PRO holds the better App Store score, 4.7 against 3.0. That said, the two scores are not equally well evidenced: Atomic Clock PRO has 10K ratings behind it against 23, so its average is the more settled of the two. Written reviews point the same way: 45% of Big Clock HD's written reviews are positive against 73% of Atomic Clock PRO's.
Big Clock HD ships an update every 29 months, Atomic Clock PRO every 3 months. The most recent releases landed on October 9, 2026 and October 13, 2026 respectively.
| Parameter | Big Clock HD | Atomic Clock PRO |
|---|---|---|
| Price | $0.49 | Free — better |
| Rating | 3.0 (23 ratings) | 4.7 (10K ratings) — better |
| Positive reviews | 45.5% of reviews | 72.9% of reviews — better |
| Number of ratings | 23 | 10K — better |
| Update frequency | Every 29 months | Every 3 months — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod, Mac, Apple TV — better | iPhone, iPad, iPod |
| Requires iOS | 14.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 1 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | TheCodingMonkeys | Brachmann Online Marketing GmbH & Co. KG |
Customer experience
Big Clock HD
Atomic Clock PRO
Bugs and requests
Big Clock HD
Not enough reviews yet to summarise bugs or requests.
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
Big Clock HD
No in-app purchases
Atomic Clock PRO
- Premium$1.991 Month
- Remove Ads$5.99
Questions
Is Big Clock HD free?
Is Atomic Clock PRO free?
Which has better reviews, Big Clock HD or Atomic Clock PRO?
Do Big Clock HD or Atomic Clock PRO have ads?
Which is updated more often, Big Clock HD or Atomic Clock PRO?
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