# Fast Slow vs Intermittently

The clearest difference is in-app purchases: Intermittently at none against Fast Slow's 4. Fast Slow's advantage is iOS requirement (18.0 vs 26.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Fast Slow sells 4 in-app purchases, starting at $1.99 per 7 days. Intermittently asks for nothing beyond the download.

Fast Slow ships an update every 2 weeks, Intermittently every 10 days. Both last shipped on October 1, 2026.

## The numbers

| Metric | Fast Slow | Intermittently |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (36 ratings)](https://appshunter.io/ios/app/fast-slow-fasting-tracker/id6749188352/reviews)** | — |
| Number of ratings | **36** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 10 days** |
| Monetization | Free | — |
| Size | 23 MB | 6 MB |
| Requires iOS | **18.0** | 26.0 |
| Devices | iPhone | **iPhone, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Zan Cerne](https://appshunter.io/developer/1747198932) | [Zachary Schiel](https://appshunter.io/developer/1877734999) |

## What reviewers say

### Fast Slow

[App page](https://appshunter.io/ios/app/fast-slow-fasting-tracker/id6749188352)

Understand your body's metabolic changes during fasting with a visual timeline. This free app guides you through different fasting zones, from digestion to deep ketosis, and offers customizable schedules and smart notifications. It provides stats, streaks, and widgets for easy progress tracking.

**Highlights:** Fasting timer with visual timeline, 6 customizable fasting schedules, 5 distinct fasting zones explained, Smart notifications for fasting windows, Stats, streaks, and trends tracking, Home and Lock Screen widgets, Siri Shortcuts integration

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Legacy | $1.99 | per 7 days |
| Legacy - Yearly | $12.99 | per year |
| Buy Me a Coffee | $2.99 | one-time |
| You're Amazing | $9.99 | one-time |


### Intermittently

[App page](https://appshunter.io/ios/app/intermittently/id6789149977)

**Features:** Family Sharing, Apple Watch app

**In-app purchases:** none


## Frequently asked questions

### Is Fast Slow free?

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

### Is Intermittently free?

Intermittently is free to download, with no in-app purchases.

### Do Fast Slow or Intermittently have ads?

Neither Fast Slow nor Intermittently shows ads.

### Which is updated more often, Fast Slow or Intermittently?

Fast Slow ships an update every 2 weeks, and Intermittently every 10 days. Most recently, Fast Slow was updated on October 1, 2026 and Intermittently on October 1, 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.*