Comparison

Interval Timer Calendar vs HIIT Timer / Interval 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 Calendar

This app helps you track your workouts with a simple timer and calendar integration. Set your training and break times, and automatically record your sessions. Save custom timers for quick access to your favorite routines.

Highlights
  • Muscle training timer
  • Automatic calendar recording
  • Save custom timer lists
  • Background operation support
  • Notification alerts
  • Workout review on calendar
Features
Read full description

It is a simple muscle training timer application that can perform timer and recording at the same time. You can start the timer as soon as you set the number of sets, training time, and break time. After the timer expires, it is automatically recorded on the calendar. If you save in the timer list in advance such as daily training, muscle training, stretching, you can always start the timer with one tap. It is automatically saved in the calendar so you can review the training content and number of times later. Because it supports the background, you can use it while listening to videos and music, and you will be notified by notification. [App Features] When using the timer, you will be notified by notification even if you do not open the app. If you write down and save the number of reps in the timer list, you can use it as a simple muscle training record. You can review past timer records on the calendar. You can use it while listening to music. If you like the app, I would be grateful if you could review it. Developers have read your reviews and are motivated!

About

HIIT Timer / Interval Timer

This app provides a customizable timer for high-intensity interval training. Easily set up warm-up, workout, and cool-down periods with adjustable intervals and counts. Personalize colors, sounds, and notifications for a tailored experience.

Highlights
  • Unlimited timer creation
  • Customizable intervals (warm-up, workout, cool-down)
  • Adjustable counts
  • Color and sound customization
  • Dark mode support
  • Background notifications
Features
Read full description

It's a timer app suitable for HIIT training. All features are completely free to use. Features: - Quick start-up and comfortable operability. Create unlimited timers. - Freely set warm-up, ready, workout, interval, cool-down minutes / seconds, and set counts. - Customize colors, texts, background notifications, sounds, speeches, vibrations, screen flashes and icon badges. - Dark mode - All free URL scheme: hiittimer:// --- * High-intensity interval training High-intensity interval training (HIIT) is a training protocol alternating short periods of intense or explosive anaerobic exercise with brief recovery periods until the point of exhaustion, which thereby relies on "the anaerobic energy releasing system almost maximally." * Procedure HIIT exercise sessions generally consist of a warm up period followed by repetitions of high-intensity exercises separated by medium intensity exercises for recovery, then a cool-down period. The high-intensity exercise should be done at near maximum intensity. The medium exercise should be about 50% intensity. The number of repetitions and length of each depends on the exercise, but maybe as little as three repetitions with just 20 seconds of intense exercise. The specific exercises performed during the high-intensity portions vary. Most of the research on HIIT has been done using a cycling ergometer, but other exercises like a rowing ergometer, running, stair climbing and uphill walking can also be effective. There is no specific formula for HIIT. Depending on one's level of cardiovascular development, the moderate-level intensity can be as slow as walking. A common formula involves a 2:1 ratio of work to recovery periods, for example, 30–40 seconds of hard sprinting alternated with 15–20 seconds of jogging or walking, repeated to failure. The entire HIIT session may last between four and thirty minutes, meaning that it is considered to be an excellent way to maximize a workout limited by time constraints. Use of a clock or timer is recommended to keep accurate times, the number of rounds, and intensity. Quoted from: https://en.wikipedia.org/wiki/High-intensity_interval_training

Screenshots

Interval Timer Calendar1 screens
HIIT Timer / Interval Timer4 screens

Verdict

The call

The clearest difference is update cadence: Interval Timer Calendar at every 3 days against HIIT Timer / Interval Timer's every 2 months. Interval Timer Calendar also leads on iOS requirement (11.0 vs 26.0). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Interval Timer Calendar ships an update every 3 days, HIIT Timer / Interval Timer every 2 months. The most recent releases landed on September 25, 2026 and September 17, 2026 respectively.

Scorecard2 real differences · 8 level
Interval Timer Calendar versus HIIT Timer / Interval Timer: the parameters behind the verdict, then further details
ParameterInterval Timer CalendarHIIT Timer / Interval Timer
PriceFreeFree
Rating—4.9 (14 ratings) — better
Positive reviews53.8% of reviews—
Number of ratings—14 — better
Update frequencyEvery 3 days — betterEvery 2 months
AdsYesYes
In-app purchasesNoNo
MonetizationAd-supportedAd-supported
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS11.0 — better26.0
Further details — not scored
Size14 MB12 MB
Age rating4+4+
Developerisao utsumiFugaPiyo Inc.

Customer experience

Interval Timer Calendar

Written reviews13 reviews
Positive53.8%
Neutral23.1%
Negative23.1%

HIIT Timer / Interval Timer

All ratings14 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Interval Timer Calendar

No in-app purchases

None

HIIT Timer / Interval Timer

No in-app purchases

Questions

Is Interval Timer Calendar free?
Interval Timer Calendar is free to download, with no in-app purchases.
Is HIIT Timer / Interval Timer free?
HIIT Timer / Interval Timer is free to download, with no in-app purchases.
Do Interval Timer Calendar or HIIT Timer / Interval Timer have ads?
Both Interval Timer Calendar and HIIT Timer / Interval Timer show ads.
Which is updated more often, Interval Timer Calendar or HIIT Timer / Interval Timer?
Interval Timer Calendar ships an update every 3 days, and HIIT Timer / Interval Timer every 2 months. Most recently, Interval Timer Calendar was updated on September 25, 2026 and HIIT Timer / Interval Timer on September 17, 2026.

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