# Atoms vs Acid Interval

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.

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.

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.

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

## The numbers

| Metric | Atoms | Acid Interval |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (11K ratings)](https://appshunter.io/ios/app/atoms-from-atomic-habits/id6474421906/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/acid-interval-focus-timer/id6815378728/reviews)** |
| Number of ratings | **11K** | 1 |
| Positive reviews | 55.9% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | Every 2 weeks |
| Monetization | Free with in-app purchases | Freemium |
| Size | 227 MB | 1 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Atomic Development Inc.](https://appshunter.io/developer/1704890395) | [Preston Carr](https://appshunter.io/developer/6815378730) |

## What reviewers say

### Atoms

[App page](https://appshunter.io/ios/app/atoms-from-atomic-habits/id6474421906)

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:** macOS Compatibility, Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Atoms Pro Monthly | $4.99 | per month |
| Atoms Pro Annual | $39.99 | per year |

**What reviewers like**

- 🚀 Simple and easy to use
- 👍 Visually appealing design
- 💡 Integrates principles from Atomic Habits book
- 🎯 Helps focus on one habit at a time
- 🔥 Motivating and encouraging

**What reviewers complain about**

- 💰 Expensive subscription price
- 🔒 Limited to only 1 or 3 habits in free version
- 🔍 Lack of flexibility to track habits not tied to specific times
- 🐛 Occasional bugs and crashes
- 🕰 Can't backlog past 24 hours

**Reported bugs**

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

**Requested features**

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


### Acid Interval

[App page](https://appshunter.io/ios/app/acid-interval-focus-timer/id6815378728)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Acid Interval Pro | $2.99 | one-time |


## Frequently asked 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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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*