Comparison

Interval Timer for HIIT | Cero vs GymTimer

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

Head to head
About

Interval Timer for HIIT | 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

GymTimer

Features
Read full description

GymTimer is a no-frills interval timer built for one thing: running your gym sets without fumbling with a stopwatch between reps. HOW IT WORKS Set your Work duration, Rest duration, and how many repetitions you want (2, 3, 4, or Unlimited) — then start training. GymTimer counts down each phase with a clear circular timer, plays a sound and vibration when a phase changes, and gives you a spoken "ten seconds" warning before rest ends so you're never caught off guard. FEATURES • Simple +/- steppers for Work and Rest durations • Set a rep target, or go Unlimited and just keep training • Big, glanceable countdown ring with phase and time remaining • Audio + haptic cues on every phase change, plus a 10-second rest warning • Pause, resume, or restart mid-session without losing your settings • Screen stays awake during a workout, so it won't lock mid-set • Your last-used settings are remembered for next time • Clean, distraction-free dark interface No accounts, no sign-up, no setup beyond picking your numbers. Just open it, set your intervals, and train.

Screenshots

Interval Timer for HIIT | Cero4 screens
GymTimer3 screens

Verdict

The call

The clearest difference is in-app purchases: GymTimer at none against Interval Timer for HIIT | Cero's 2. GymTimer also leads on update cadence (daily vs every 3 days). On price, ads, device support and iOS requirement 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. Interval Timer for HIIT | Cero sells 2 in-app purchases, starting at $2.99 per month. GymTimer asks for nothing beyond the download.

UpkeepUpdate frequency

Interval Timer for HIIT | Cero ships an update every 3 days, GymTimer daily. The most recent releases landed on October 20, 2026 and October 3, 2026 respectively.

Scorecard2 real differences · 8 level
Interval Timer for HIIT | Cero versus GymTimer: the parameters behind the verdict, then further details
ParameterInterval Timer for HIIT | CeroGymTimer
PriceFreeFree
Rating4.7 (436 ratings) — better—
Positive reviews74.6% of reviews—
Number of ratings436 — better—
Update frequencyEvery 3 daysDaily — better
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS16.0 — better16.4
Further details — not scored
Size42 MB40 MB
Age rating4+4+
DeveloperFlawless Studio LLCAndrea Gioco

Bugs and requests

Interval Timer for HIIT | 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

GymTimer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Interval Timer for HIIT | Cero

Subscriptions1
  • Cero Pro Monthly7 Days trial$2.991 Month
One-time1
  • Cero Pro$14.99
None

GymTimer

No in-app purchases

Questions

Is Interval Timer for HIIT | Cero free?
Interval Timer for HIIT | Cero is free to download, with in-app purchases available.
Is GymTimer free?
GymTimer is free to download, with no in-app purchases.
Do Interval Timer for HIIT | Cero or GymTimer have ads?
Both Interval Timer for HIIT | Cero and GymTimer show ads.
Which is updated more often, Interval Timer for HIIT | Cero or GymTimer?
Interval Timer for HIIT | Cero ships an update every 3 days, and GymTimer daily. Most recently, Interval Timer for HIIT | Cero was updated on October 20, 2026 and GymTimer on October 3, 2026.

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