# Interval Timer for HIIT | Cero vs Gustav Workout Timer

The clearest difference is rating: Interval Timer for HIIT | Cero at 4.7 against Gustav Workout Timer's 4.1. Interval Timer for HIIT | Cero also leads on update cadence (every 3 days vs monthly) and ratings volume (441 vs 8). Gustav Workout Timer's advantage is in-app purchases (none vs 2) and ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Interval Timer for HIIT | Cero sells 2 in-app purchases, starting at $2.99 per month. Gustav Workout Timer asks for nothing beyond the download.

Interval Timer for HIIT | Cero holds the better App Store score, 4.7 against 4.1. That said, the two scores are not equally well evidenced: Interval Timer for HIIT | Cero has 441 ratings behind it against 8, so its average is the more settled of the two. Written reviews complicate that: 75% of Interval Timer for HIIT | Cero's written reviews are positive against 100% of Gustav Workout Timer's, so the app with the better star average is not the one people write more warmly about.

Interval Timer for HIIT | Cero ships an update every 3 days, Gustav Workout Timer monthly. The most recent releases landed on November 13, 2026 and November 12, 2026 respectively.

## The numbers

| Metric | Interval Timer for HIIT | Cero | Gustav Workout Timer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (441 ratings)](https://appshunter.io/ios/app/interval-timer-for-hiit-cero/id1256319392/reviews)** | [4.1 (8 ratings)](https://appshunter.io/ios/app/gustav-workout-timer/id6478176431/reviews) |
| Number of ratings | **441** | 8 |
| Positive reviews | 74.6% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 3 days** | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 59 MB | 31 MB |
| Requires iOS | 18.0 | 18.0 |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Flawless Studio LLC](https://appshunter.io/developer/1228312508) | [Dalibor Janecek](https://appshunter.io/developer/1732114572) |

## What reviewers say

### Interval Timer for HIIT | Cero

[App page](https://appshunter.io/ios/app/interval-timer-for-hiit-cero/id1256319392)

Create custom interval workouts for HIIT, Tabata, and circuit training. This app offers detailed programming with custom intervals, colors, and icons. Stay focused with large controls, clear cues, and optional heart rate training.

**Highlights:** Customizable interval programming, Heart rate training integration, Live Activities and Dynamic Island support, Siri and Shortcuts integration, Workout history and calorie tracking, Apple Watch app, Shareable timers

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cero Pro Monthly | $2.99 | per month |
| Cero Pro | $14.99 | one-time |

**What reviewers like**

- 👍 Simple and straightforward
- 👍 Very practical and customizable
- 👍 Great for HIIT and Tabata
- 👍 Clear design and easy to use
- 👍 Good value, no subscription

**What reviewers complain about**

- 🔋 Drains battery
- 🎶 Music playback interrupted
- ⚠️ Ads interrupt timers
- 🔊 Weak or non-functional sound/haptics
- 🔄 Forced updates

**Reported bugs**

- App runs in background draining battery
- Rotation broke after update
- Apple workout app overrides Cero app on Apple Watch
- Interval signals too weak or not working

**Requested features**

- Ability to group timers
- Option to add warm-up and cool-down features
- Ability to type numbers for time adjustment
- Timer sounds through headphones or interrupting music
- Ability to change exercise names


### Gustav Workout Timer

[App page](https://appshunter.io/ios/app/gustav-workout-timer/id6478176431)

This app helps you manage your workout intervals for various training types like HIIT, circuits, and strength. It offers customizable timers, built-in options, and personalized interval naming for a focused and comfortable training experience.

**Highlights:** Customizable intervals up to 10 minutes, Ready-made built-in timers, Save custom timers to Favourites, Custom interval naming, New sound and audio cue options, Haptic feedback for interval changes, Modern Liquid Glass design

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

**In-app purchases:** none


## Frequently asked questions

### Is Interval Timer for HIIT | Cero free?

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

### Is Gustav Workout Timer free?

Gustav Workout Timer is free to download, with no in-app purchases.

### Which has better reviews, Interval Timer for HIIT | Cero or Gustav Workout Timer?

Interval Timer for HIIT | Cero is rated higher. Interval Timer for HIIT | Cero averages 4.7 out of 5 from 441 ratings, while Gustav Workout Timer averages 4.1 from 8 ratings.

### Do Interval Timer for HIIT | Cero or Gustav Workout Timer have ads?

Interval Timer for HIIT | Cero shows ads; Gustav Workout Timer does not.

### Which is updated more often, Interval Timer for HIIT | Cero or Gustav Workout Timer?

Interval Timer for HIIT | Cero ships an update every 3 days, and Gustav Workout Timer monthly. Most recently, Interval Timer for HIIT | Cero was updated on November 13, 2026 and Gustav Workout Timer on November 12, 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.*