# UniTimer vs HIIT Interval Timer | Cero

The clearest difference is in-app purchases: UniTimer at none against HIIT Interval Timer | Cero's 1. UniTimer also leads on review sentiment (97% vs 75%) and iOS requirement (10.0 vs 16.0). HIIT Interval Timer | Cero's advantage is update cadence (every 3 days vs every 6 months) and ratings volume (435 vs 15). On price, rating, ads and device support there is nothing between them.

Both are free to download. HIIT Interval Timer | Cero sells 1 one-off in-app purchase. 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 HIIT Interval Timer | Cero. That said, the two scores are not equally well evidenced: HIIT Interval Timer | Cero has 435 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 HIIT Interval Timer | Cero's.

UniTimer ships an update every 6 months, HIIT Interval Timer | Cero every 3 days. The most recent releases landed on September 20, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | UniTimer | HIIT Interval Timer | Cero |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (15 ratings)](https://appshunter.io/ios/app/unitimer/id590573213/reviews)** | [4.7 (435 ratings)](https://appshunter.io/ios/app/hiit-interval-timer-cero/id1256319392/reviews) |
| Number of ratings | 15 | **435** |
| 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 | 42 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


### HIIT Interval Timer | Cero

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Cero Pro | $3.99 | 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 HIIT Interval Timer | Cero free?

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

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

UniTimer is rated higher. UniTimer averages 4.8 out of 5 from 15 ratings, while HIIT Interval Timer | Cero averages 4.7 from 435 ratings.

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

Both UniTimer and HIIT Interval Timer | Cero show ads.

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

UniTimer ships an update every 6 months, and HIIT Interval Timer | Cero every 3 days. Most recently, UniTimer was updated on September 20, 2026 and HIIT Interval Timer | Cero on September 25, 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.*