# Justfit vs IntervalTimer Duo

The clearest difference is ads: IntervalTimer Duo at none against Justfit's shown. Justfit's advantage is update cadence (every 3 days vs every 3 weeks) and iOS requirement (15.0 vs 26.1). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Justfit sells 5 in-app purchases, starting at $2.99 per month and IntervalTimer Duo sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Justfit ships an update every 3 days, IntervalTimer Duo every 3 weeks. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Justfit | IntervalTimer Duo |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/justfit-boxing-interval-timer/id6449503037/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 3 days** | Every 3 weeks |
| Monetization | Free with in-app purchases | — |
| Size | 116 MB | 10 MB |
| Requires iOS | **15.0** | 26.1 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Ferda Nahit Fidanci](https://appshunter.io/developer/1689464732) | [kosuke konuma](https://appshunter.io/developer/1767116232) |

## What reviewers say

### Justfit

[App page](https://appshunter.io/ios/app/justfit-boxing-interval-timer/id6449503037)

This interval timer app allows users to create custom workout routines like Tabata, HIIT, or boxing circuits with customizable intervals and voice announcements. It offers background operation, Apple Watch integration, and detailed workout history.

**Highlights:** Unlimited custom intervals, sets, and rest periods, Voice announcements and countdowns, Background operation with large display, Apple Watch app and Lock Screen Live Activity, Workout history and weekly insights, Widgets and Siri integration

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $2.99 | per month |
| Annual | $14.99 | per year |
| Justfit Pro Annual | $14.99 | per year |
| Justfit Pro Lifetime | $22.99 | one-time |
| Lifetime access | $29.99 | one-time |


### IntervalTimer Duo

[App page](https://appshunter.io/ios/app/intervaltimer-duo/id6753626424)

**Features:** Family Sharing, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version | $2.99 | one-time |


## Frequently asked questions

### Is Justfit free?

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

### Is IntervalTimer Duo free?

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

### Do Justfit or IntervalTimer Duo have ads?

Justfit shows ads; IntervalTimer Duo does not.

### Which is updated more often, Justfit or IntervalTimer Duo?

Justfit ships an update every 3 days, and IntervalTimer Duo every 3 weeks. Most recently, Justfit was updated on November 3, 2026 and IntervalTimer Duo on October 30, 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.*