# My DuIN vs SmartFasting

The clearest difference is in-app purchases: My DuIN at none against SmartFasting's 1. My DuIN also leads on iOS requirement (15.0 vs 26.2). SmartFasting's advantage is update cadence (every 2 weeks vs every 2 months). On price, ads and device support there is nothing between them.

Both are free to download. SmartFasting sells 1 one-off in-app purchase. My DuIN asks for nothing beyond the download.

My DuIN ships an update every 2 months, SmartFasting every 2 weeks. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | My DuIN | SmartFasting |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/my-duin/id1578864033/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 88.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Free | — |
| Size | 173 MB | 2 MB |
| Requires iOS | **15.0** | 26.2 |
| Devices | **iPhone, iPod, Apple Watch** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Duet Spa & Sports, SL](https://appshunter.io/developer/1516601322) | [Juan Delgado](https://appshunter.io/developer/1873096811) |

## What reviewers say

### My DuIN

[App page](https://appshunter.io/ios/app/my-duin/id1578864033)

Monitor workouts, track progress, and achieve fitness goals with personalized plans and engaging challenges. Seamlessly record gym sessions or manual entries, and book classes to stay motivated.

**Highlights:** Workout tracking, Personalized training plans, Activity level monitoring, Fun challenges with rewards, Class scheduling and booking, HealthKit integration

**Features:** macOS Compatibility, Apple Wallet, Apple Watch app, Vision Pro support

**In-app purchases:** none


### SmartFasting

[App page](https://appshunter.io/ios/app/smartfasting/id6758466557)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SmartFast Premium | $4.99 | one-time |


## Frequently asked questions

### Is My DuIN free?

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

### Is SmartFasting free?

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

### Do My DuIN or SmartFasting have ads?

Neither My DuIN nor SmartFasting shows ads.

### Which is updated more often, My DuIN or SmartFasting?

My DuIN ships an update every 2 months, and SmartFasting every 2 weeks. Most recently, My DuIN was updated on October 24, 2026 and SmartFasting on October 28, 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.*