# UniTimer vs Interval Timer for HIIT | Cero

The clearest difference is in-app purchases: UniTimer at none against Interval Timer for HIIT | Cero's 2. UniTimer also leads on review sentiment (97% vs 75%) and iOS requirement (10.0 vs 16.0). Interval Timer for HIIT | Cero's advantage is update cadence (every 3 days vs every 6 months) and ratings volume (438 vs 15). On price, rating, ads and device support 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. UniTimer asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.8 for UniTimer against 4.7 for Interval Timer for HIIT | Cero. That said, the two scores are not equally well evidenced: Interval Timer for HIIT | Cero has 438 ratings behind it against 15, so its average is the more settled of the two. Written reviews are what separate them: 97% of UniTimer's written reviews are positive against 75% of Interval Timer for HIIT | Cero's.

UniTimer ships an update every 6 months, Interval Timer for HIIT | Cero every 3 days. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | UniTimer | Interval Timer for HIIT | Cero |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (15 ratings)](https://appshunter.io/ios/app/unitimer/id590573213/reviews)** | [4.7 (438 ratings)](https://appshunter.io/ios/app/interval-timer-for-hiit-cero/id1256319392/reviews) |
| Number of ratings | 15 | **438** |
| Positive reviews | **96.9% of reviews** | 74.6% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 6 months | **Every 3 days** |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 14 MB | 45 MB |
| Requires iOS | **10.0** | 16.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [AlexApps.Net Co](https://appshunter.io/developer/972261962) | [Flawless Studio LLC](https://appshunter.io/developer/1228312508) |

## What reviewers say

### UniTimer

[App page](https://appshunter.io/ios/app/unitimer/id590573213)

Create personalized timers for any routine with custom text, colors, and sounds.  Set notifications, use your own music or voice, and add custom images. Works in the background with built-in music controls.

**Highlights:** Customizable text and colors, Notification options, Customizable sound alerts, Image integration, Background operation, Pre-built routine sets

**Features:** macOS Compatibility

**In-app purchases:** none


### Interval Timer for HIIT | Cero

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

This interval timer app enhances various workouts like HIIT, Tabata, and yoga with intuitive design and customizable timer modes. Create and save custom intervals, track calorie expenditure, and sync settings across devices, including Apple Watch.

**Highlights:** Customizable interval timers, Simple and advanced timer modes, Create and save multiple workout settings, Apple Watch compatibility with heart monitor, Automatic calorie tracking to Apple Health, Cross-device sync

**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


## Frequently asked questions

### Is UniTimer free?

UniTimer is free to download, with no in-app purchases.

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

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

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

UniTimer is rated higher. UniTimer averages 4.8 out of 5 from 15 ratings, while Interval Timer for HIIT | Cero averages 4.7 from 438 ratings.

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

Both UniTimer and Interval Timer for HIIT | Cero show ads.

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

UniTimer ships an update every 6 months, and Interval Timer for HIIT | Cero every 3 days. Most recently, UniTimer was updated on November 1, 2026 and Interval Timer for HIIT | Cero on November 2, 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.*