# Fast Slow vs Fasting Center

The clearest difference is in-app purchases: Fasting Center at none against Fast Slow's 4. Fasting Center also leads on update cadence (every 3 days vs every 2 weeks) and device support (4 vs 1). Fast Slow's advantage is rating (5.0 vs 4.8). On price, review sentiment, ratings volume and ads there is nothing between them.

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

Fast Slow holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 39 and 25 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Fast Slow ships an update every 2 weeks, Fasting Center every 3 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Fast Slow | Fasting Center |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (39 ratings)](https://appshunter.io/ios/app/fast-slow-fasting-tracker/id6749188352/reviews)** | [4.8 (25 ratings)](https://appshunter.io/ios/app/fasting-center-fast-tracker/id6780227473/reviews) |
| Number of ratings | **39** | 25 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 3 days** |
| Monetization | Free | Free |
| Size | 23 MB | 48 MB |
| Requires iOS | 18.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod, Apple Watch** |
| Age rating | 4+ | 12+ |
| Developer | [Zan Cerne](https://appshunter.io/developer/1747198932) | [Andrey Titov](https://appshunter.io/developer/6780227475) |

## 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 |


### Fasting Center

[App page](https://appshunter.io/ios/app/fasting-center-fast-tracker/id6780227473)

Plan extended fasts with personalized projections. Input your body stats and desired duration to estimate weight change, fat loss, and energy use. This data-driven tool provides a clear starting point for your fasting journey.

**Highlights:** Personalized fast planning, Extended fast duration options, Projected weight change, Estimated fat loss, Energy use projection, Data-driven starting point

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

**In-app purchases:** none


## Frequently asked questions

### Is Fast Slow free?

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

### Is Fasting Center free?

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

### Which has better reviews, Fast Slow or Fasting Center?

Fast Slow is rated higher. Fast Slow averages 5.0 out of 5 from 39 ratings, while Fasting Center averages 4.8 from 25 ratings.

### Do Fast Slow or Fasting Center have ads?

Neither Fast Slow nor Fasting Center shows ads.

### Which is updated more often, Fast Slow or Fasting Center?

Fast Slow ships an update every 2 weeks, and Fasting Center every 3 days. Most recently, Fast Slow was updated on October 24, 2026 and Fasting Center on October 25, 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.*