# RUN interval vs Fartlek Interval Trainer

The clearest difference is update cadence: Fartlek Interval Trainer at every 9 days against RUN interval's every 3 months. RUN interval's advantage is iOS requirement (15.6 vs 26.0). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. RUN interval sells 2 one-off in-app purchases and Fartlek Interval Trainer sells 4 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

RUN interval ships an update every 3 months, Fartlek Interval Trainer every 9 days. The most recent releases landed on September 25, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | RUN interval | Fartlek Interval Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (1K ratings)](https://appshunter.io/ios/app/run-interval-running-timer/id1352270752/reviews)** | — |
| Number of ratings | **1K** | — |
| Positive reviews | **77.5% of reviews** | 75.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 9 days** |
| Monetization | Free with in-app purchases | Freemium |
| Size | 34 MB | 84 MB |
| Requires iOS | **15.6** | 26.0 |
| Devices | **iPhone, iPod, Apple Watch** | iPhone, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [CAN YOU HEAR ME SOFTWARE](https://appshunter.io/developer/711042540) | [Richard English](https://appshunter.io/developer/1537547687) |

## What reviewers say

### RUN interval

[App page](https://appshunter.io/ios/app/run-interval-running-timer/id1352270752)

This app simplifies interval and Fartlek running by allowing you to set custom targets for time or distance during hard, easy, and rest efforts. It offers detailed post-run summaries, audio and visual feedback, and an Apple Watch app for enhanced training.

**Highlights:** Customizable interval sessions, Time and distance targets, Distance Goal option, Audio and visual feedback, Detailed run summaries, Apple Watch app, Strava sharing

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| The full RUN interval | $1.99 | one-time |
| The full RUN interval | $3.99 | one-time |


### 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 |


## Frequently asked questions

### Is RUN interval free?

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

### Is Fartlek Interval Trainer free?

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

### Do RUN interval or Fartlek Interval Trainer have ads?

Neither RUN interval nor Fartlek Interval Trainer shows ads.

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

RUN interval ships an update every 3 months, and Fartlek Interval Trainer every 9 days. Most recently, RUN interval was updated on September 25, 2026 and Fartlek Interval Trainer on September 22, 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.*