# Zero vs AllyFast

Zero and AllyFast both sit at 4.8 stars, but that hides the real split: 100% of AllyFast's written reviews are positive against 32% of Zero's. AllyFast also leads on in-app purchases (none vs 10). Zero's advantage is price (Free vs $0.99) and ratings volume (445K vs 22). On rating, ads, device support and iOS requirement there is nothing between them.

Zero is free to download; AllyFast costs $0.99 up front. Zero sells 7 in-app purchases, starting at $9.99 per month. AllyFast asks for nothing beyond the download.

AllyFast holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Zero has 445K ratings behind it against 22, so its average is the more settled of the two. Written reviews point the same way: 32% of Zero's written reviews are positive against 100% of AllyFast's.

Zero ships an update every 2 weeks, AllyFast monthly. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Zero | AllyFast |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | [4.8 (445K ratings)](https://appshunter.io/ios/app/zero-fasting-and-food-tracker/id1168348542/reviews) | **[5.0 (22 ratings)](https://appshunter.io/ios/app/allyfast-fasting-tracker/id6743131202/reviews)** |
| Number of ratings | **445K** | 22 |
| Positive reviews | 32.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Monthly |
| Monetization | **Freemium** | Paid |
| Best chart rank | **#102** | — |
| Size | 195 MB | 2 MB |
| Requires iOS | **17.0** | 18.2 |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Zero Longevity Science, Inc.](https://appshunter.io/developer/1397458636) | [Wonseok Lee](https://appshunter.io/developer/1801568032) |

## What reviewers say

### Zero

[App page](https://appshunter.io/ios/app/zero-fasting-and-food-tracker/id1168348542)

**Currently charting:** #102 Top Grossing · Health & Fitness (US App Store)

This app tracks intermittent fasting and nutrition to help users achieve real body composition changes. It integrates fasting, protein intake, meals, hydration, and habits for a holistic approach to weight loss and metabolic health.

**Highlights:** Intermittent fasting timers and streaks, Smart meal logging with photo recognition, Personalized daily protein target tracking, Integrated fasting and protein tracking, Water and habit tracking, Science-based insights on fasting and nutrition

**Features:** Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Zero Plus Subscription | $9.99 | per month |
| Zero Plus Subscription | $9.99 | per month |
| Zero Plus Subscription | $69.99 | per year |
| Zero Plus Subscription | $69.99 | per year |
| Zero Plus Subscription | $69.99 | per year |
| Zero Plus Subscription | $69.99 | per year |
| Zero Plus Subscription | $89.99 | per year |

**What reviewers like**

- 🚀 Easy to use
- 📊 Helpful tracking and data
- 💡 Informative learning resources
- 🔍 Detailed fasting information
- 🤝 Sense of community

**What reviewers complain about**

- 💰 Expensive premium subscription
- 🔒 Forced account creation
- 🙄 Intrusive ads and upsells
- 🤔 Inconsistent or confusing UI changes
- 🐛 Syncing and login issues

**Reported bugs**

- Password reset problems
- Inaccurate fasting time tracking
- Inability to exit trial without subscribing

**Requested features**

- Custom fasting periods longer than 24 hours
- Ability to edit fasting type and duration
- Integration with more health/fitness apps
- Water intake tracking
- Personalized fasting recommendations


### AllyFast

[App page](https://appshunter.io/ios/app/allyfast-fasting-tracker/id6743131202)

This app offers a streamlined fasting timer with a clean, SwiftUI-based interface. It prioritizes user privacy with local data storage and provides science-based insights into fasting stages. Enjoy a clutter-free, ad-free experience with no subscriptions.

**Highlights:** SwiftUI fasting timer, Local data storage, No subscriptions or ads, Fasts up to 72 hours, Editable fasting history, Science-based fasting insights

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Zero free?

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

### Is AllyFast free?

AllyFast costs $0.99, with no in-app purchases.

### Which has better reviews, Zero or AllyFast?

AllyFast is rated higher. Zero averages 4.8 out of 5 from 445K ratings, while AllyFast averages 5.0 from 22 ratings.

### Do Zero or AllyFast have ads?

Neither Zero nor AllyFast shows ads.

### Which is updated more often, Zero or AllyFast?

Zero ships an update every 2 weeks, and AllyFast monthly. Most recently, Zero was updated on November 4, 2026 and AllyFast on October 30, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*