# Fartlek Interval Trainer vs Leptin

The clearest difference is iOS requirement: Leptin at 15.1 against Fartlek Interval Trainer's 26.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Fartlek Interval Trainer sells 4 in-app purchases, starting at $0.99 per month and Leptin sells 10 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

Fartlek Interval Trainer ships an update weekly, Leptin every 5 days. The most recent releases landed on October 9, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Fartlek Interval Trainer | Leptin |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Weekly | **Every 5 days** |
| Monetization | Freemium | — |
| Size | 85 MB | 56 MB |
| Requires iOS | 26.0 | **15.1** |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Richard English](https://appshunter.io/developer/1537547687) | [GRAYLIN AI (PTY) LTD](https://appshunter.io/developer/1872989548) |

## What reviewers say

### Fartlek Interval Trainer

[App page](https://appshunter.io/ios/app/fartlek-interval-trainer/id1537547685)

This running app automatically detects spontaneous intervals during Fartlek runs, providing live color-coded feedback on your effort. It also functions as a powerful timer for structured workouts like HIIT and Tabata, offering detailed metrics and syncing with Strava and Apple Health.

**Highlights:** Auto-detection of Fartlek intervals, Live color-coded effort feedback, Structured workout timer (HIIT, Tabata), Detailed interval metrics, Strava and Apple Health integration, Advanced effort level detection

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $0.99 | per month |
| Annual | $6.99 | per year |
| RemoveAds | $0.99 | one-time |
| Lifetime | $14.99 | one-time |


### Leptin

[App page](https://appshunter.io/ios/app/leptin/id6765621429)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basic Monthly | $9.99 | per month |
| Premium Monthly | $19.99 | per month |
| Unlimited Monthly | $49.99 | per month |
| Basic Yearly | $99.99 | per year |
| Premium Yearly | $199.99 | per year |
| Unlimited Yearly | $499.99 | per year |
| $10 AI Credits | $12.99 | one-time |
| $25 AI Credits | $32.99 | one-time |
| $50 AI Credits | $64.99 | one-time |
| $100 AI Credits | $129.99 | one-time |


## Frequently asked questions

### Is Fartlek Interval Trainer free?

Fartlek Interval Trainer is free to download, with in-app purchases available.

### Is Leptin free?

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

### Do Fartlek Interval Trainer or Leptin have ads?

Neither Fartlek Interval Trainer nor Leptin shows ads.

### Which is updated more often, Fartlek Interval Trainer or Leptin?

Fartlek Interval Trainer ships an update weekly, and Leptin every 5 days. Most recently, Fartlek Interval Trainer was updated on October 9, 2026 and Leptin on October 11, 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.*