Comparison

Atoms vs Acid Interval

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

Head to head
About

Atoms

This app helps you build good habits and break bad ones using principles from a best-selling book. It offers bite-sized lessons, guided habit creation, and smart reminders to make positive changes in just five minutes a day.

Highlights
  • Guided habit creation
  • Bite-sized lessons
  • Smart reminders
  • Progress insights
  • Intuitive interface
  • Apple Watch app
Features
Read full description

Introducing Atoms – The Official Atomic Habits App! ## Tiny changes, remarkable results! ## Atoms is the definitive habits forming app inspired by the groundbreaking principles of Atomic Habits, the best-selling book by James Clear. Atoms is not only a habit tracker, but also your personal guide filled with bite-sized lessons and insightful strategies to help you make positive changes one small step at a time. # WHY ATOMS? * Proven Principles: Atoms is crafted on the science-backed principles of habit change covered in Atomic Habits. You will learn how to make your habits obvious, attractive, easy, and satisfying. * Five Good Minutes: Experience powerful change in just five minutes a day! Atoms is designed for everyone, including those with busy lifestyles, ensuring that you can build good habits, break bad ones, and make better decisions with minimal time investment. * NYT Best-Seller: Join over 15 million people who have already embraced the transformative power of Atomic Habits. Atoms brings these life-changing principles and James Clear’s content to your fingertips in an easy-to-use app. # KEY FEATURES: * Guided Habit Creation: Start small and build habits based on the kind of person you want to become. Get guidance on how to start at the right size for you. Create consistency by committing to a time and place. Build habits that last. * Intuitive Interface: Enjoy a seamless user interface that makes habit tracking a joy. Visualize your progress, celebrate milestones, and stay motivated with every tiny win. * Smart Reminders: Never miss a moment to invest in yourself. Atoms uses smart reminders to keep you on track and encourage consistent habit-building. * Progress Insights: Gain valuable insights into your habits with detailed analytics. Track your progress over time, identify patterns, and make informed decisions for continuous improvement. * Apple Watch app: Log your habits on the move Download Atoms now and start experiencing the power of Atomic Habits. Think big. Start Small. Use Atoms. Terms and Conditions - https://www.iubenda.com/terms-and-conditions/22673733 Privacy Policy - https://www.iubenda.com/privacy-policy/22673733 End User License Agreement - https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Acid Interval

This focus timer offers a visually unique approach to deep work, moving away from traditional interfaces. It provides customizable timers and engaging visual feedback to help users stay on task, even with the screen off. The app prioritizes a distraction-free experience with no account or data syncing required.

Highlights
  • Unique visual interface
  • Customizable timer intervals
  • Engaging animation mechanisms
  • Screen-off notifications
  • No account or data sync
  • Phone lock compatibility
Read full description

A focus timer worth looking at. Most focus timers look like a spreadsheet with a countdown in it. This one is built the other way round. A single enormous numeral, bleeding off the edge of a field of acid green. Behind it, a mechanism that moves in time with the clock and never drifts. Rings that bounce, breathe, ripple inward, or pass momentum down a Newton's cradle. A square whose perimeter burns like a fuse, four seconds a side, for box breathing. When you start a session the whole field inverts to black and the numbers light up like something switched on behind them. Tap anywhere to start. Swipe to change the color. You never have to open a menu. 25/5, 50/10, 90/20, or count up. The classic pomodoro, longer ultradian blocks, or open-ended flow when you don't want a deadline. Timed properly. Built on timestamps, not ticks. Lock your phone, switch apps, come back: it is exactly where it should be. It tells you when you are done, even with the screen off. No account. No sync. No data leaves your phone. ACID INTERVAL PRO One payment unlocks all eight mechanisms, all ten colorways, and custom interval lengths. The timer itself is free and always will be.

Screenshots

Atoms4 screens
Acid Interval4 screens

Verdict

The call

The clearest difference is ratings volume: Atoms at 11K against Acid Interval's 1. On price, rating, update cadence and ads 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. Atoms sells 2 in-app purchases, starting at $4.99 per month and Acid Interval 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

Acid Interval holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Atoms has 11K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 weeks. The most recent releases landed on October 30, 2026 and October 22, 2026 respectively.

Scorecard1 real difference · 9 level
Atoms versus Acid Interval: the parameters behind the verdict, then further details
ParameterAtomsAcid Interval
PriceFreeFree
Rating4.8 (11K ratings)5.0 (1 ratings) — better
Positive reviews55.9% of reviews—
Number of ratings11K — better1
Update frequencyEvery 2 weeksEvery 2 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFreemium
DevicesiPhone, Apple Watch — betteriPhone
Requires iOS16.0 — better17.0
Further details — not scored
Size227 MB1 MB
Age rating4+4+
DeveloperAtomic Development Inc.Preston Carr

Customer experience

Atoms

All ratings10,650 ratings
Positive95.9%
Neutral1.7%
Negative2.4%
Written reviews706 reviews
Positive55.9%
Neutral12.3%
Negative31.7%

Acid Interval

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Atoms

Reported bugs

3 issues
  • Login issues and app freezes
  • Habit progress not saving correctly
  • Widget not functioning as expected

Requested features

5 requests
  • Dark mode option
  • Ability to track more habits
  • More customization options for habits
  • Improved data visualization and analytics
  • Accountability partner features

Acid Interval

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Atoms

Subscriptions2
  • Atoms Pro Monthly$4.991 Month
  • Atoms Pro Annual$39.991 Year
1 purchases

Acid Interval

One-time1
  • Acid Interval Pro$2.99

Questions

Is Atoms free?
Atoms is free to download, with in-app purchases available.
Is Acid Interval free?
Acid Interval is free to download, with in-app purchases available.
Which has better reviews, Atoms or Acid Interval?
Acid Interval is rated higher. Atoms averages 4.8 out of 5 from 11K ratings, while Acid Interval averages 5.0 from 1 ratings.
Do Atoms or Acid Interval have ads?
Neither Atoms nor Acid Interval shows ads.
Which is updated more often, Atoms or Acid Interval?
Atoms ships an update every 2 weeks, and Acid Interval every 2 weeks. Most recently, Atoms was updated on October 30, 2026 and Acid Interval on October 22, 2026.

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