Comparison

Interval Timer for HIIT | Cero vs Amelia Timer

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

Create custom interval workouts for HIIT, Tabata, and circuit training. Features adaptive heart rate training, Siri integration, and Apple Watch support. Track progress and share your custom routines.

Highlights
  • Customizable interval programming
  • Adaptive heart rate training
  • Siri and Shortcuts integration
  • Apple Watch app
  • Workout history and sharing
  • Live Activities and Dynamic Island support
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

Amelia Timer

This app provides a straightforward interval timer for various activities. Easily configure your work and rest periods, and the number of repetitions needed. It's designed for simplicity, offering essential timer functions without unnecessary complexity.

Highlights
  • Customizable action and break lengths
  • Adjustable number of sets
  • Notifications when app is closed
  • Audible cues for set/break starts
  • Countdown ticks
  • Remembers last used settings
Features
Read full description

Simple, beautiful and completely free interval timer. Just a couple taps to set your interval length, break length, and number of sets. No ads, no bloat, just a simple periodic timer. Perfect for stretching, running, yoga, or any other interval exercises. You can use it as a Pomodoro timer, tabata timer, or other HIIT timer! Other apps include complicated features and user interfaces. This app is for people that don't need all the bells and whistles. Features include: - Customize action length, break length, and how many sets you want to complete - Receive notifications while the app is closed - Pleasant sounds played when each set and break begins - Helpful 3... 2... 1... ticks to know you're reaching the end - Remembers the last settings you use for simple re-use

Screenshots

Interval Timer for HIIT | Cero4 screens
Amelia Timer4 screens

Verdict

The call

The clearest difference is in-app purchases: Amelia Timer at none against Interval Timer for HIIT | Cero's 2. Amelia Timer also leads on ads (none vs shown) and update cadence (daily vs every 3 days). Interval Timer for HIIT | Cero's advantage is ratings volume (438 vs 60). On price, rating, review sentiment 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. Interval Timer for HIIT | Cero sells 2 in-app purchases, starting at $2.99 per month. Amelia Timer asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Interval Timer for HIIT | Cero against 4.7 for Amelia Timer. That said, the two scores are not equally well evidenced: Interval Timer for HIIT | Cero has 438 ratings behind it against 60, so its average is the more settled of the two. Written reviews are what separate them: 75% of Interval Timer for HIIT | Cero's written reviews are positive against 81% of Amelia Timer's.

UpkeepUpdate frequency

Interval Timer for HIIT | Cero ships an update every 3 days, Amelia Timer daily. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

Scorecard6 real differences · 4 level
Interval Timer for HIIT | Cero versus Amelia Timer: the parameters behind the verdict, then further details
ParameterInterval Timer for HIIT | CeroAmelia Timer
PriceFreeFree
Rating4.7 (438 ratings) — better4.7 (60 ratings)
Positive reviews74.6% of reviews80.8% of reviews — better
Number of ratings438 — better60
Update frequencyEvery 3 daysDaily — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Apple WatchiPhone, iPad, iPod
Requires iOS18.011.0 — better
Further details — not scored
Size50 MB18 MB
Age rating4+4+
DeveloperFlawless Studio LLCSean Linehan

Customer experience

Interval Timer for HIIT | Cero

All ratings438 ratings
Positive92.9%
Neutral3.9%
Negative3.2%
Written reviews59 reviews
Positive74.6%
Neutral10.2%
Negative15.3%

Amelia Timer

All ratings60 ratings
Positive90.0%
Neutral6.7%
Negative3.3%
Written reviews26 reviews
Positive80.8%
Neutral15.4%
Negative3.8%

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

Amelia Timer

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

Amelia Timer

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 Amelia Timer free?
Amelia Timer is free to download, with no in-app purchases.
Which has better reviews, Interval Timer for HIIT | Cero or Amelia Timer?
Interval Timer for HIIT | Cero is rated higher. Interval Timer for HIIT | Cero averages 4.7 out of 5 from 438 ratings, while Amelia Timer averages 4.7 from 60 ratings.
Do Interval Timer for HIIT | Cero or Amelia Timer have ads?
Interval Timer for HIIT | Cero shows ads; Amelia Timer does not.
Which is updated more often, Interval Timer for HIIT | Cero or Amelia Timer?
Interval Timer for HIIT | Cero ships an update every 3 days, and Amelia Timer daily. Most recently, Interval Timer for HIIT | Cero was updated on November 6, 2026 and Amelia Timer on November 2, 2026.

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