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 custom interval training circuits and run them with precision timing, voice announcements, and haptic feedback. CREATE YOUR PERFECT WORKOUT Design circuits with unlimited intervals, each with its own name, duration, and alarm sound. Set loop counts on individual intervals or the entire circuit. Choose from 24 alarm sounds, enable voice countdown, or both. STAY IN THE ZONE A full-screen player with a progress ring, countdown timer, and interval timeline keeps you focused. The last 3 seconds pulse to keep you ready for what's next. Voice announcements call out interval names so you never have to look at your screen. NEVER MISS A BEAT Live Activities put your timer on the Lock Screen and Dynamic Island. Background notifications keep you on track even when you switch apps. Start circuits hands-free with Siri. APPLE WATCH Run circuits from your wrist with real-time heart rate zones, active calories, and haptic alerts. Your watch keeps going even when the screen dims with Always-On Display support. TRACK YOUR PROGRESS View workout history with streaks, completion stats, and total training time. Save workouts to Apple Health as High Intensity Interval Training sessions. FREE TO START - 1 circuit with full features β€” alarms, haptics, voice, history CORE UPGRADE - Unlimited circuits - iCloud sync across devices - Apple Health integration PRO UPGRADE - Everything in Core - Apple Watch companion app 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 monthly) 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 monthly. The most recent releases landed on September 14, 2026 and September 3, 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€” betterMonthly
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 monthly. Most recently, Kaizen Timer was updated on September 14, 2026 and Circuit Timer on September 3, 2026.

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