# Tranquil vs Interval Timer | HIIT Training

Tranquil and Interval Timer | HIIT Training are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Tranquil sells 10 in-app purchases, starting at $4.99 per month and Interval Timer | HIIT Training sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

Tranquil ships an update fortnightly, Interval Timer | HIIT Training every 10 days. The most recent releases landed on October 24, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Tranquil | Interval Timer | HIIT Training |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/interval-timer-hiit-training/id6791772563/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Fortnightly | **Every 10 days** |
| Monetization | — | Free with in-app purchases |
| Size | 147 MB | 86 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Apple TV** | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Future Watch Technologies (Private) Limited](https://appshunter.io/developer/1847897090) | [LS PROGRAMACAO LTDA](https://appshunter.io/developer/1896779603) |

## What reviewers say

### Tranquil

[App page](https://appshunter.io/ios/app/tranquil-sleep-and-relax/id6772150691)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Tranquil Monthly Premium | $4.99 | per month |
| Crackling Fire | $1.99 | one-time |
| Distant Thunder | $1.99 | one-time |
| Wind Chimes | $1.99 | one-time |
| Autumn Leaves | $1.99 | one-time |
| First Snow | $1.99 | one-time |
| Nature Escapes Pack | $3.99 | one-time |
| Calm and Grounded Pack | $3.99 | one-time |
| Study Pack | $3.99 | one-time |
| Sleep Pack | $3.99 | one-time |


### Interval Timer | HIIT Training

[App page](https://appshunter.io/ios/app/interval-timer-hiit-training/id6791772563)

This app provides a customizable interval timer for various training activities like HIIT and Tabata. Users can build custom workouts with named phases, sounds, and vibrations, and save them as presets that sync across devices. It also supports background operation with screen off.

**Highlights:** Customizable workout builder, Nestable repeat blocks, Custom phases with names, colors, sounds, and vibrations, Drag and drop reordering, Save and reuse workout presets, Syncs between iPhone and Apple Watch, Background operation with screen off

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Interval Timer Pro Monthly | $1.99 | per month |
| Interval Timer Pro Annual | $11.99 | per year |
| Interval Timer Pro Lifetime | $29.99 | one-time |


## Frequently asked questions

### Is Tranquil free?

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

### Is Interval Timer | HIIT Training free?

Interval Timer | HIIT Training is free to download, with in-app purchases available.

### Do Tranquil or Interval Timer | HIIT Training have ads?

Both Tranquil and Interval Timer | HIIT Training show ads.

### Which is updated more often, Tranquil or Interval Timer | HIIT Training?

Tranquil ships an update fortnightly, and Interval Timer | HIIT Training every 10 days. Most recently, Tranquil was updated on October 24, 2026 and Interval Timer | HIIT Training on October 18, 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.*