Comparison

Circuit Training Timer Lite 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

Circuit Training Timer Lite

This app coaches your workouts with customizable timers, allowing you to focus on training. It supports location tracking for detailed statistics and heart rate monitoring with Bluetooth LE devices. Voice coaching and clear visual cues keep you informed without needing to check your screen.

Highlights
  • Customizable interval timers
  • Location tracking for stats
  • Bluetooth LE heart rate monitor support
  • Voice coaching and notifications
  • Workout history tracking
  • iCloud synchronization
Features
Read full description

Let our timer to coach your workouts so you can focus on actual training without staring at the watch. This timer meets the needs of amateurs as well as professionals. It was designed to be flexible and highly customisable so it can be used for all kinds of trainings. There is one important difference between this app and other apps on the App Store. No need to change timer configuration when switching exercises all the time. Create and configure timers once and use them multiple times. For more demanding users timers can be composed into entire workouts. All timers and workouts can be categorized into groups. For each timer can be enabled location tracking. With enabled location tracking you can seethe route and location based statistics like distance, speed, pace and altitude. Another great feature is support for heart rate training using a Bluetooth LE heart rate monitor. User can create multiple profiles and switch between them. Heart rate training profile contains all settings for your training like heart rate zones and notification options. During exercising user can be notified about current heart rate and zone. One heart rate zone can be selected as target zone. Voice coaching can notify the user to adjust tempo to stay in current zone. The user interface is designed to be clear and readable from a distance. For notification can be used vibrations, sounds and also text to speech voice. No more looking at the screen to know the current interval. Each timer is composed from intervals. Each interval has a configurable name, duration, color and music. Music can be set also for whole timer. Your workout sessions can be saved into history where you can see how you performed during exercising. All your timers and workout history can be synchronized into iCloud. Features: - Support for Apple Health (only for Full Version) - Synchronization to iCloud (only for Full Version) - Heart rate training feature. - Location tracking feature. - Timer sounds: last seconds, every second, interval end, timer finish and metronome. - Timer vibrations: last seconds, interval end and timer finish. - Timer text to speech voice: interval name, next interval name, duration at beginning of interval, current interval time, counting down for last seconds and timer finish. - Timers can be easily shared and duplicated. - Timers can be categorised into groups. - Timer music (playlist, album or song). - Multiple screens for running timer with different stats: Map, Location, Heart Rate, Timer, Intervals and Music - User can configure visual style for timer screens. - Screens for running timer can be locked. - Each interval has configurable duration, name, color and music. - Runs and plays music on background. - Universal app, works on iPhone and iPad. - Max interval duration is 99 hours 59 minutes and 59 seconds. - Max number of sets is 999. Free version includes ads and other restrictions that can be removed with InApp Purchases. If you have enable Track Location option please note: Continued use of GPS running in the background can dramatically decrease battery life.

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

Circuit Training Timer Lite4 screens
HIIT Interval Timer | Cero4 screens

Verdict

The call

The clearest difference is ads: Circuit Training Timer Lite at none against HIIT Interval Timer | Cero's shown. Circuit Training Timer Lite also leads on review sentiment (85% vs 75%) and iOS requirement (12.0 vs 16.0). HIIT Interval Timer | Cero's advantage is update cadence (every 3 days vs every 6 weeks). On price, rating, ratings volume and in-app purchases 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. Circuit Training Timer Lite sells 3 one-off in-app purchases and HIIT Interval Timer | Cero sells 2 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for Circuit Training Timer Lite against 4.7 for HIIT Interval Timer | Cero. Both are backed by a comparable volume of ratings — 468 and 435 respectively. Written reviews are what separate them: 85% of Circuit Training Timer Lite's written reviews are positive against 75% of HIIT Interval Timer | Cero's.

UpkeepUpdate frequency

Circuit Training Timer Lite ships an update every 6 weeks, HIIT Interval Timer | Cero every 3 days. The most recent releases landed on October 11, 2026 and October 12, 2026 respectively.

Scorecard4 real differences · 6 level
Circuit Training Timer Lite versus HIIT Interval Timer | Cero: the parameters behind the verdict, then further details
ParameterCircuit Training Timer LiteHIIT Interval Timer | Cero
PriceFreeFree
Rating4.8 (468 ratings) — better4.7 (435 ratings)
Positive reviews84.6% of reviews — better74.6% of reviews
Number of ratings468 — better435
Update frequencyEvery 6 weeksEvery 3 days — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, Apple Watch
Requires iOS12.0 — better16.0
Further details — not scored
Size36 MB43 MB
Age rating4+4+
DeveloperDenciSoft s.r.o.Flawless Studio LLC

Customer experience

Circuit Training Timer Lite

All ratings468 ratings
Positive97.0%
Neutral1.1%
Negative1.9%
Written reviews78 reviews
Positive84.6%
Neutral5.1%
Negative10.3%

HIIT Interval Timer | Cero

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

User reviews

Circuit Training Timer Lite

From 468 App Store ratings

What we love

  • 👍 Highly customizable workouts
  • 🎶 Music integration
  • ⏱️ Flexible timer settings
  • 🔊 Voice prompts for exercises
  • 📚 Saved workout routines

Room to improve

  • 🔋 Battery drain issues
  • 🔒 Limited functionality in free version
  • 🔇 Quiet audio prompts
  • 📈 Lack of workout history/progress tracking

HIIT Interval Timer | Cero

From 435 App Store ratings

What we love

  • 👍 Simple and straightforward
  • 👍 Very practical and customizable
  • 👍 Great for HIIT and Tabata
  • 👍 Clear design and easy to use
  • 👍 Good value, no subscription

Room to improve

  • 🔋 Drains battery
  • 🎶 Music playback interrupted
  • ⚠️ Ads interrupt timers
  • 🔊 Weak or non-functional sound/haptics
  • 🔄 Forced updates

Bugs and requests

Circuit Training Timer Lite

Reported bugs

2 issues
  • Playlist sync issues
  • App crashes when phone is locked

Requested features

4 requests
  • Ability to share workout routines
  • Integration with fitness tracking apps
  • More advanced statistics and analytics
  • Apple Watch app support

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

3 purchases

Circuit Training Timer Lite

One-time3
  • Remove Ads$1.99
  • Unlimited Timers$1.99
  • Full Version$2.99
2 purchases

HIIT Interval Timer | Cero

Subscriptions1
  • Cero Pro Monthly7 Days trial$2.991 Month
One-time1
  • Cero Pro$14.99

Questions

Is Circuit Training Timer Lite free?
Circuit Training Timer Lite is free to download, with in-app purchases available.
Is HIIT Interval Timer | Cero free?
HIIT Interval Timer | Cero is free to download, with in-app purchases available.
Which has better reviews, Circuit Training Timer Lite or HIIT Interval Timer | Cero?
Circuit Training Timer Lite is rated higher. Circuit Training Timer Lite averages 4.8 out of 5 from 468 ratings, while HIIT Interval Timer | Cero averages 4.7 from 435 ratings.
Do Circuit Training Timer Lite or HIIT Interval Timer | Cero have ads?
HIIT Interval Timer | Cero shows ads; Circuit Training Timer Lite does not.
Which is updated more often, Circuit Training Timer Lite or HIIT Interval Timer | Cero?
Circuit Training Timer Lite ships an update every 6 weeks, and HIIT Interval Timer | Cero every 3 days. Most recently, Circuit Training Timer Lite was updated on October 11, 2026 and HIIT Interval Timer | Cero on October 12, 2026.

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