# Flow Fasting Tracker vs Rhythmus

The clearest difference is in-app purchases: Rhythmus at none against Flow Fasting Tracker's 2. Rhythmus also leads on update cadence (daily vs every 10 days). Flow Fasting Tracker's advantage is iOS requirement (13.0 vs 15.0). On price, ads and device support there is nothing between them.

Both are free to download. Flow Fasting Tracker sells 2 in-app purchases, starting at $7.99 per month. Rhythmus asks for nothing beyond the download.

Flow Fasting Tracker ships an update every 10 days, Rhythmus daily. The most recent releases landed on October 13, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Flow Fasting Tracker | Rhythmus |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 10 days | **Daily** |
| Size | 16 MB | 20 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kristina Kozicynaite](https://appshunter.io/developer/1882882099) | [Patrick Sarpen](https://appshunter.io/developer/6804829454) |

## What reviewers say

### Flow Fasting Tracker

[App page](https://appshunter.io/ios/app/flow-fasting-tracker/id6776109275)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $7.99 | per month |
| Annual | $39.99 | per year |


### Rhythmus

[App page](https://appshunter.io/ios/app/rhythmus-cycle-syncing/id6804829452)

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

**In-app purchases:** none


## Frequently asked questions

### Is Flow Fasting Tracker free?

Flow Fasting Tracker is free to download, with in-app purchases available.

### Is Rhythmus free?

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

### Do Flow Fasting Tracker or Rhythmus have ads?

Neither Flow Fasting Tracker nor Rhythmus shows ads.

### Which is updated more often, Flow Fasting Tracker or Rhythmus?

Flow Fasting Tracker ships an update every 10 days, and Rhythmus daily. Most recently, Flow Fasting Tracker was updated on October 13, 2026 and Rhythmus 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.*