Comparison

Kaizen Timer vs Circuit Timer

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

Head to head
About

Kaizen Timer

Features
Read full description

Kaizen Timer is a customizable interval timer for boxing, HIIT, Tabata, treadmill workouts, strength training, and more. Build simple work–rest intervals or create advanced multi-phase workouts that match exactly how you train. Start quickly with ready-made presets, or customize every phase, round, work period, and rest period. FEATURES β€’ Presets for popular training styles β€’ Fully customizable work and rest intervals β€’ Advanced phase sequencing for complex workouts β€’ Clear visual and audio timers β€’ Accurate round and phase tracking β€’ Reliable timing when backgrounded or locked β€’ Home Screen widgets for quick access β€’ Light and dark mode support β€’ Optional Apple Health integration for workouts and calorie estimation β€’ Export completed workouts β€’ Available in multiple languages, including: English, French, German, Italian, Russian, Spanish, Japanese, Chinese BUILT FOR CONSISTENCY Set your training intensity and let Kaizen Timer handle the structure. Timers stay accurate even during interruptions, helping you stay focused through every round. FREE TO USE All Kaizen Timer features are available for free. An optional support subscription helps fund ongoing development, but subscribing is never required to access features or content. Train smarter. Stay focused. Improve every round. Terms of Use: https://kaizentimerapp.com/terms.html Privacy Policy: https://kaizentimerapp.com/privacy.html

About

Circuit Timer

Features
Read full description

Build your own interval circuits for HIIT, Tabata, boxing rounds, EMOM and circuit training, then run them with precise timing, voice announcements, sounds and haptics. CREATE YOUR PERFECT WORKOUT Design circuits with unlimited intervals, each with its own name, duration and alarm sound. Repeat single intervals or the whole circuit, by count or for a set time. Choose from 24 alarm sounds, a spoken countdown, or both. STAY IN THE ZONE A full-screen player with a progress ring, countdown and interval timeline keeps you focused. The final seconds of each interval pulse so you're ready for what's next, and voice announcements call out each interval by name, so you never have to look at your screen. TRAIN WITH YOUR MUSIC Interval sounds play over your music instead of pausing it. The current interval and countdown stay on your Lock Screen and in the Dynamic Island, and cues keep working through phone calls. Start any circuit hands-free with Siri. APPLE WATCH Run circuits from your wrist with live heart rate, heart rate zones, active calories and a tap at every interval change. Starting a workout on your iPhone? Your watch follows along with the same taps and your heart rate. A Smart Stack card keeps the current interval in view, even with the app closed. TRACK YOUR PROGRESS See your workout history with streaks, completion stats and total training time. Save workouts to Apple Health as High Intensity Interval Training. FREE TO START β€’ 1 circuit with every feature: alarms, haptics, voice and history CORE UPGRADE β€’ Unlimited circuits β€’ iCloud sync across your devices β€’ Apple Health PRO UPGRADE β€’ Everything in Core β€’ Apple Watch app Both upgrades are one-time purchases. No subscription. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Kaizen Timer4 screens
Circuit Timer3 screens

Verdict

The call

The clearest difference is in-app purchases: Kaizen Timer at none against Circuit Timer's 2. Kaizen Timer also leads on update cadence (every 3 days vs every 6 weeks) and iOS requirement (17.6 vs 26.0). On price, ads and device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. Circuit Timer sells 2 one-off in-app purchases. Kaizen Timer asks for nothing beyond the download.

UpkeepUpdate frequency

Kaizen Timer ships an update every 3 days, Circuit Timer every 6 weeks. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

Scorecard3 real differences Β· 3 level
Kaizen Timer versus Circuit Timer: the parameters behind the verdict, then further details
ParameterKaizen TimerCircuit Timer
PriceFreeFree
Update frequencyEvery 3 days β€” betterEvery 6 weeks
AdsNoNo
In-app purchasesNo β€” betterYes
DevicesiPhone, iPadiPhone, iPad, Apple Watch β€” better
Requires iOS17.6 β€” better26.0
Further details β€” not scored
Size3 MB7 MB
Age rating4+4+
DeveloperStefan DasicLawman Services, LLC

In-app purchases

None

Kaizen Timer

No in-app purchases

2 purchases

Circuit Timer

One-time2
  • Core$2.99
  • Pro$4.99

Questions

Is Kaizen Timer free?
Kaizen Timer is free to download, with no in-app purchases.
Is Circuit Timer free?
Circuit Timer is free to download, with in-app purchases available.
Do Kaizen Timer or Circuit Timer have ads?
Neither Kaizen Timer nor Circuit Timer shows ads.
Which is updated more often, Kaizen Timer or Circuit Timer?
Kaizen Timer ships an update every 3 days, and Circuit Timer every 6 weeks. Most recently, Kaizen Timer was updated on October 25, 2026 and Circuit Timer on October 24, 2026.

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