# Rhythm vs Fast Slow

The clearest difference is in-app purchases: Rhythm at none against Fast Slow's 4. Rhythm also leads on ratings volume (458 vs 39). Fast Slow's advantage is update cadence (every 2 weeks vs every 13 months) and rating (5.0 vs 4.7). On price, ads, monetization model 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. Rhythm asks for nothing beyond the download.

Fast Slow holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Rhythm has 458 ratings behind it against 39, so its average is the more settled of the two. Written reviews point the same way: 89% of Rhythm's written reviews are positive against 100% of Fast Slow's.

Rhythm ships an update every 13 months, Fast Slow every 2 weeks. The most recent releases landed on November 2, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Rhythm | Fast Slow |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (458 ratings)](https://appshunter.io/ios/app/rhythm-fasting-tracker/id1377199450/reviews) | **[5.0 (39 ratings)](https://appshunter.io/ios/app/fast-slow-fasting-tracker/id6749188352/reviews)** |
| Number of ratings | **458** | 39 |
| Positive reviews | 88.6% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 13 months | **Every 2 weeks** |
| Monetization | Free | Free |
| Size | 3 MB | 23 MB |
| Requires iOS | **17.6** | 18.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Bijan Cronin](https://appshunter.io/developer/1377199449) | [Zan Cerne](https://appshunter.io/developer/1747198932) |

## What reviewers say

### Rhythm

[App page](https://appshunter.io/ios/app/rhythm-fasting-tracker/id1377199450)

This app simplifies intermittent fasting with a daily tracker. It supports various fasting schedules, from beginner-friendly to advanced, and helps users monitor their progress over time. Get notifications when your fast is complete.

**Highlights:** Daily fasting tracker, Flexible schedule support, Weekly progress tracking, Customizable fasting goals, One-click start, Progress monitoring, Completion notifications

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 💎 Simple and easy to use
- 🆓 Free app with no ads or subscriptions
- ⏱️ Straightforward fasting timer
- 📊 Tracks fasting progress
- 🔍 Allows editing of start/end times

**What reviewers complain about**

- ⏰ Can't track fasts longer than 24 hours
- 📅 Limited history view (only past week)
- 🔔 Lacks customizable notifications/reminders

**Reported bugs**

- Can't add past fasts
- Inconsistent weekly progress tracking

**Requested features**

- Ability to track longer fasts (e.g., 48-72 hours)
- Option to view fasting history beyond the past week
- Customizable notifications and reminders
- Integration with health/fitness tracking apps
- Weight tracking and progress visualization


### 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 |


## Frequently asked questions

### Is Rhythm free?

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

### Is Fast Slow free?

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

### Which has better reviews, Rhythm or Fast Slow?

Fast Slow is rated higher. Rhythm averages 4.7 out of 5 from 458 ratings, while Fast Slow averages 5.0 from 39 ratings.

### Do Rhythm or Fast Slow have ads?

Neither Rhythm nor Fast Slow shows ads.

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

Rhythm ships an update every 13 months, and Fast Slow every 2 weeks. Most recently, Rhythm was updated on November 2, 2026 and Fast Slow on November 5, 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.*