# Intermittent Fasting vs Shifting Source

The clearest difference is in-app purchases: Shifting Source at none against Intermittent Fasting's 3. Intermittent Fasting's advantage is update cadence (every 3 days vs every 9 days) and iOS requirement (16.4 vs 26.0). On price, ads and device support there is nothing between them.

Both are free to download. Intermittent Fasting sells 3 in-app purchases, starting at $1.99 per 7 days. Shifting Source asks for nothing beyond the download.

Intermittent Fasting ships an update every 3 days, Shifting Source every 9 days. The most recent releases landed on October 12, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Intermittent Fasting | Shifting Source |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 9 days |
| Size | 68 MB | 9 MB |
| Requires iOS | **16.4** | 26.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [Sylvain Fertons](https://appshunter.io/developer/1851147694) | [Hejlsvig Consulting AB](https://appshunter.io/developer/1895103789) |

## What reviewers say

### Intermittent Fasting

[App page](https://appshunter.io/ios/app/intermittent-fasting-biwo/id6771495054)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Biwo Pro Weekly | $1.99 | per 7 days |
| Biwo Pro Monthly | $4.99 | per month |
| Biwo Pro Yearly | $49.99 | per year |


### Shifting Source

[App page](https://appshunter.io/ios/app/shifting-source/id6789093040)

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

**In-app purchases:** none


## Frequently asked questions

### Is Intermittent Fasting free?

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

### Is Shifting Source free?

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

### Do Intermittent Fasting or Shifting Source have ads?

Neither Intermittent Fasting nor Shifting Source shows ads.

### Which is updated more often, Intermittent Fasting or Shifting Source?

Intermittent Fasting ships an update every 3 days, and Shifting Source every 9 days. Most recently, Intermittent Fasting was updated on October 12, 2026 and Shifting Source on October 15, 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.*