# FastSloth vs Buff

The clearest difference is in-app purchases: Buff at none against FastSloth's 1. Buff also leads on iOS requirement (18.2 vs 26.0). FastSloth's advantage is ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. FastSloth sells 1 one-off in-app purchase. Buff asks for nothing beyond the download.

FastSloth ships an update every 6 days, Buff every 5 days. The most recent releases landed on October 16, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | FastSloth | Buff |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/fastsloth-fasting-tracker/id6759827972/reviews)** | — |
| Number of ratings | **4** | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 6 days | **Every 5 days** |
| Monetization | Free with in-app purchases | — |
| Size | 9 MB | 69 MB |
| Requires iOS | 26.0 | **18.2** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Darren Paul](https://appshunter.io/developer/1874841503) | [SPACEMANCODES LTD](https://appshunter.io/developer/6805952604) |

## What reviewers say

### FastSloth

[App page](https://appshunter.io/ios/app/fastsloth-fasting-tracker/id6759827972)

This app helps you track intermittent fasting with customizable schedules and real-time indicators of your body's stages. It also includes hydration logging, weight tracking with visual progress charts, and smart notifications to keep you on track. All your data stays private on your device.

**Highlights:** Customizable fasting schedules, Real-time ketosis and autophagy indicators, Hydration logging and reminders, Weight tracking with progress charts, Streak tracking and milestone badges, Home screen widgets, Private, no account required

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Lifetime | $1.99 | one-time |


### Buff

[App page](https://appshunter.io/ios/app/buff-health-and-progress/id6805952212)

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

**In-app purchases:** none


## Frequently asked questions

### Is FastSloth free?

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

### Is Buff free?

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

### Do FastSloth or Buff have ads?

Buff shows ads; FastSloth does not.

### Which is updated more often, FastSloth or Buff?

FastSloth ships an update every 6 days, and Buff every 5 days. Most recently, FastSloth was updated on October 16, 2026 and Buff on October 9, 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.*