Comparison

UniTimer vs HIIT Interval Timer | Cero

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

UniTimer

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
Read full description

UniTimer is the Universal Timer app. You can build any kind of routine: - Custom text - Custom colors - Option for notifications - Custom melodies or your iPod music or even your own voice - Custom pictures from library or your camera - Customizable interval ending notice Application comes with pre-built sets for different use cases: - HIIT Training - Boxing Rounds - Tooth Brushing - Take Turns in Gaming - and others UniTimer works in background or while your device is locked. iPod controls are build-in and music plays while UniTimer is active.

About

HIIT Interval Timer | Cero

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
Read full description

Build an interval workout around the way you train. Cero is a flexible interval timer for HIIT, Tabata, circuit training, WODs and HYROX preparation. Set up a quick work/rest timer or program each interval in detail. Distinct colors, large controls and reliable cues keep you focused on the session instead of the clock. BUILD YOUR SESSION • Set work, recovery, sets, warm-up and cool-down. • Create advanced workouts with custom intervals, colors, icons and intensity levels. • Save, duplicate and reorder timers. • Share timers by file or QR code. • Review completed sessions in workout history. STAY IN THE WORKOUT • Follow compatible sessions with Live Activities and Dynamic Island. • Start saved or recent timers from Home Screen widgets. • Use Siri and Shortcuts to start, pause, resume and stop a timer. • Put Gym Display on a larger screen or mirrored TV. • Choose a default song or assign music to individual intervals. • Customize sounds, voice cues, vibrations and background alerts. TRAIN BY HEART RATE Adaptive HR can extend recovery until you reach your target heart rate, then guide hard efforts with low and high alerts. Pair a Bluetooth heart-rate monitor with iPhone or train with heart-rate data from Apple Watch. COUNTDOWN AND STOPWATCH The built-in countdown and lap stopwatch cover warm-ups, station changes, rest periods and race-day practice. Stopwatch sessions continue after you close and reopen the app. ON APPLE WATCH Run saved workouts from your wrist, follow heart rate and use the standalone countdown and stopwatch. Cero can save completed workouts and estimated calories to Apple Health. Automatic iCloud backups help protect saved timers and custom intervals. Useful for HIIT, Tabata, circuits, EMOM-style workouts, boxing rounds, strength and conditioning, indoor cycling, running intervals and hybrid race preparation. Feedback and suggestions: hi@flawless.studio Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

UniTimer3 screens
HIIT Interval Timer | Cero4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. HIIT Interval Timer | Cero sells 1 one-off in-app purchase. UniTimer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard6 real differences · 4 level
UniTimer versus HIIT Interval Timer | Cero: the parameters behind the verdict, then further details
ParameterUniTimerHIIT Interval Timer | Cero
PriceFreeFree
Rating4.8 (15 ratings) — better4.7 (435 ratings)
Positive reviews96.9% of reviews — better74.6% of reviews
Number of ratings15435 — better
Update frequencyEvery 6 monthsEvery 3 days — better
AdsYesYes
In-app purchasesNo — betterYes
MonetizationAd-supported — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, Apple Watch
Requires iOS10.0 — better16.0
Further details — not scored
Size14 MB42 MB
Age rating4+4+
DeveloperAlexApps.Net CoFlawless Studio LLC

Customer experience

UniTimer

All ratings15 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews32 reviews
Positive96.9%
Neutral0.0%
Negative3.1%

HIIT Interval Timer | Cero

All ratings435 ratings
Positive92.9%
Neutral3.9%
Negative3.2%
Written reviews59 reviews
Positive74.6%
Neutral10.2%
Negative15.3%

Bugs and requests

UniTimer

Not enough reviews yet to summarise bugs or requests.

HIIT Interval Timer | Cero

Reported bugs

4 issues
  • 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

5 requests
  • 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

In-app purchases

None

UniTimer

No in-app purchases

1 purchases

HIIT Interval Timer | Cero

One-time1
  • Cero Pro$3.99

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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