Comparison

HIIT Interval Timer | Cero vs Interval Timer

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

Head to head
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/

About

Interval Timer

This app provides a customizable interval timer for various workout types, including HIIT and Tabata. It features a minimalist design, audio guidance, rep counting, and workout history tracking. You can use your favorite music apps while training.

Highlights
  • Customizable timers and presets
  • Audio guidance and beep sounds
  • Rep counting functionality
  • Workout history and calendar view
  • Minimalist and glanceable design
  • Music app integration
Features
Read full description

Core is a professional interval timer for your daily workouts! - Workout with music: just use your favorite music apps while training. - Count Reps: can be used as a counter to count your workout reps. - Minimalist design: elegant interface and glanceable from afar. - Customizable timers: simple to create your own timers and save presets. - Audio Guide: beep sounds to use in noisy environments and voice guidance. - Workout history: keep track of your workout with stats and calendar view. - Suitable for all kinds of interval training: HIIT, Tabata, boxing, yoga, calisthenics, CrossFit, cardio exercises, circuit training and etc. This app includes optional auto-renewable subscriptions: Monthly ($1.99), Yearly ($7.99). Your subscription will be charged to your iTunes account at confirmation of purchase and will automatically renew (at the duration selected) unless auto-renew is turned off at least 24 hours before the end of the current period. Current subscription may not be canceled during the active subscription period; however, you can manage your subscription and/or turn off auto-renewal by visiting your iTunes Account Settings after purchase. Privacy policy: https://xydigital.studio/Privacy-Policy-4e08709f9d9144558415c7776536786d Terms of use: https://xydigital.studio/Terms-of-Use-5d480081e6624643a7ac87cc87caf9f9 If you have any ideas to improve the App, please contact us via coretimerapp@gmail.com. Your feedback is highly valued!

Screenshots

HIIT Interval Timer | Cero4 screens
Interval Timer4 screens

Verdict

The call

The clearest difference is ads: Interval Timer at none against HIIT Interval Timer | Cero's shown. Interval Timer also leads on review sentiment (100% vs 75%) and rating (5.0 vs 4.7). HIIT Interval Timer | Cero's advantage is update cadence (every 3 days vs every 3 weeks) and ratings volume (435 vs 3). On price, in-app purchases, monetization model 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 and Interval Timer sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Interval Timer holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: HIIT Interval Timer | Cero has 435 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 75% of HIIT Interval Timer | Cero's written reviews are positive against 100% of Interval Timer's.

UpkeepUpdate frequency

HIIT Interval Timer | Cero ships an update every 3 days, Interval Timer every 3 weeks. The most recent releases landed on September 29, 2026 and September 23, 2026 respectively.

Scorecard6 real differences · 4 level
HIIT Interval Timer | Cero versus Interval Timer: the parameters behind the verdict, then further details
ParameterHIIT Interval Timer | CeroInterval Timer
PriceFreeFree
Rating4.7 (435 ratings)5.0 (3 ratings) — better
Positive reviews74.6% of reviews100.0% of reviews — better
Number of ratings435 — better3
Update frequencyEvery 3 days — betterEvery 3 weeks
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPod
Requires iOS16.09.0 — better
Further details — not scored
Size42 MB91 MB
Age rating4+4+
DeveloperFlawless Studio LLCYating Lu

Customer experience

HIIT Interval Timer | Cero

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

Interval Timer

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and 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

Interval Timer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

HIIT Interval Timer | Cero

One-time1
  • Cero Pro$3.99
3 purchases

Interval Timer

Subscriptions2
  • Monthly$1.991 Month
  • Yearly$7.991 Year
One-time1
  • Lifetime$9.99

Questions

Is HIIT Interval Timer | Cero free?
HIIT Interval Timer | Cero is free to download, with in-app purchases available.
Is Interval Timer free?
Interval Timer is free to download, with in-app purchases available.
Which has better reviews, HIIT Interval Timer | Cero or Interval Timer?
Interval Timer is rated higher. HIIT Interval Timer | Cero averages 4.7 out of 5 from 435 ratings, while Interval Timer averages 5.0 from 3 ratings.
Do HIIT Interval Timer | Cero or Interval Timer have ads?
HIIT Interval Timer | Cero shows ads; Interval Timer does not.
Which is updated more often, HIIT Interval Timer | Cero or Interval Timer?
HIIT Interval Timer | Cero ships an update every 3 days, and Interval Timer every 3 weeks. Most recently, HIIT Interval Timer | Cero was updated on September 29, 2026 and Interval Timer on September 23, 2026.

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