# Fast Slow vs FastFox

The clearest difference is ads: Fast Slow at none against FastFox's shown. Fast Slow also leads on update cadence (fortnightly vs every 2 months). FastFox's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 18.0). On price and in-app purchases there is nothing between them.

Both are free to download. Fast Slow sells 4 in-app purchases, starting at $1.99 per 7 days and FastFox sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Fast Slow ships an update fortnightly, FastFox every 2 months. The most recent releases landed on September 13, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Fast Slow | FastFox |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (22 ratings)](https://appshunter.io/ios/app/fast-slow-fasting-tracker/id6749188352/reviews)** | — |
| Number of ratings | **22** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Fortnightly** | Every 2 months |
| Monetization | Free | — |
| Size | 19 MB | 51 MB |
| Requires iOS | 18.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Zan Cerne](https://appshunter.io/developer/1747198932) | [MyQuietSpot Inc.](https://appshunter.io/developer/1841316087) |

## 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 |


### FastFox

[App page](https://appshunter.io/ios/app/fastfox-intermittent-fasting/id6761245094)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FastFox Pro | $14.99 | one-time |


## Frequently asked questions

### Is Fast Slow free?

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

### Is FastFox free?

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

### Do Fast Slow or FastFox have ads?

FastFox shows ads; Fast Slow does not.

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

Fast Slow ships an update fortnightly, and FastFox every 2 months. Most recently, Fast Slow was updated on September 13, 2026 and FastFox on September 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.*