# Atomic Fast vs Unthink

The clearest difference is update cadence: Atomic Fast at every 4 days against Unthink's every 3 weeks. Atomic Fast also leads on device support (3 vs 1). Unthink's advantage is iOS requirement (16.4 vs 18.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Atomic Fast sells 3 in-app purchases, starting at $4.99 per month and Unthink sells 2 in-app purchases, starting at $8.99 per month. Whichever you choose, the download price is not the number that matters.

Atomic Fast ships an update every 4 days, Unthink every 3 weeks. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Atomic Fast | Unthink |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (30 ratings)](https://appshunter.io/ios/app/atomic-fast-fasting-and-diet/id6763870543/reviews)** | — |
| Number of ratings | **30** | — |
| Positive reviews | 96.3% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 3 weeks |
| Monetization | Freemium | — |
| Size | 22 MB | 53 MB |
| Requires iOS | 18.0 | **16.4** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Startise](https://appshunter.io/developer/1895534080) | [Nico Lange](https://appshunter.io/developer/6797797100) |

## What reviewers say

### Atomic Fast

[App page](https://appshunter.io/ios/app/atomic-fast-fasting-and-diet/id6763870543)

This app combines intermittent fasting with AI-powered calorie and macro tracking. It analyzes your eating patterns, hydration, sleep, and activity to provide metabolic insights and a daily readiness score. Seamlessly integrates with Apple Health for a holistic view of your well-being.

**Highlights:** AI calorie and macro estimation from photos, Intermittent fasting timer with metabolic phases, Break-fast meal scoring and suggestions, Connects meals and fasts for holistic insights, Daily readiness score based on health signals, Apple Health and Apple Watch integration

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Atomic+ Monthly | $4.99 | per month |
| Atomic+ Annual | $29.99 | per year |
| Atomic+ Lifetime | $59.99 | one-time |


### Unthink

[App page](https://appshunter.io/ios/app/unthink-stop-overthinking/id6813588513)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $8.99 | per month |
| Yearly | $44.99 | per year |


## Frequently asked questions

### Is Atomic Fast free?

Atomic Fast is free to download, with in-app purchases available.

### Is Unthink free?

Unthink is free to download, with in-app purchases available.

### Do Atomic Fast or Unthink have ads?

Neither Atomic Fast nor Unthink shows ads.

### Which is updated more often, Atomic Fast or Unthink?

Atomic Fast ships an update every 4 days, and Unthink every 3 weeks. Most recently, Atomic Fast was updated on October 28, 2026 and Unthink on October 24, 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.*