# Fartlek Interval Trainer vs Phase

The clearest difference is iOS requirement: Phase at 16.4 against Fartlek Interval Trainer's 26.0. On price, ads, in-app purchases and device support 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 Phase sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | Fartlek Interval Trainer | Phase |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Weekly | — |
| Monetization | Freemium | — |
| Size | 85 MB | 53 MB |
| Requires iOS | 26.0 | **16.4** |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Richard English](https://appshunter.io/developer/1537547687) | [ZHUYE DENG](https://appshunter.io/developer/6793344095) |

## 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 |


### Phase

[App page](https://appshunter.io/ios/app/phase-interval-trainer/id6794157434)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Phase Lifetime | $8.99 | one-time |


## Frequently asked questions

### Is Fartlek Interval Trainer free?

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

### Is Phase free?

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

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

Neither Fartlek Interval Trainer nor Phase shows ads.

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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.*