Comparison

Simple Interval Timer vs Whistle Timer

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

Head to head
About

Simple Interval Timer

This app provides a straightforward interval timer for various training types like running, cycling, and HIIT. Customize sets, action, and break durations for a personalized workout experience. It runs in the background and saves recent configurations.

Highlights
  • Customizable sets, action, and break durations
  • Plain and simple design
  • Saves last 5 configurations
  • Runs in the background
  • iOS screen dimming prevention
  • Apple Watch integration with heart rate monitoring
Features
Read full description

Simple Interval Timer (SIT) can be used for any kind of interval training, such as running, cycling, HIIT sessions (including Tabata method), stretching, etc. SIT is exactly what you would expect. An interval timer, which is easy to set up and use. It features a nice plain design, with no unnecessary controls. Adjust Number of Sets, Action and Break duration to your needs and you are ready to go! On the iOS an extra switch control allows you to prevent the screen from dimming. SIT remembers the last 5 configurations you have used. Swipe left across the Settings screen to switch to another configuration. SIT can run in the background, while you are playing music, watching videos or doing anything else on your iOS device. SIT Watch features the same simplicity as the iOS app while offering the same functionality, plus it will measure your heartbeat during the workout sessions. The recordings will be available in the Apple's Health app. SIT Watch runs independently of the phone, so no need to have your phone around during your workouts (although you will need your phone during the very first time you launch SIT watch). SIT lets you avoid any tedious set up and focus on your training!

About

Whistle Timer

Create custom workout schedules with customizable work and break intervals. Save your training plans for future use and focus on your fitness goals. The app can run in the background to keep your workout on track.

Highlights
  • Customizable workout schedules
  • Add custom breaks
  • Save training plans
  • Background operation
  • Whistle sound option
Features
Read full description

Whistle Timer lets you create a customised working schedule without anything unnecessary. - Blow a whistle forever - Add customised breaks - Focus on your workout! - Save your plans for further use - Run on the background

Screenshots

Simple Interval Timer4 screens
Whistle Timer4 screens

Verdict

The call

The clearest difference is review sentiment: Simple Interval Timer at 85% against Whistle Timer's 29%. Simple Interval Timer also leads on rating (4.9 vs 4.4) and ratings volume (5.4K vs 99). Whistle Timer's advantage is ads (none vs shown). On price, update cadence, 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. Simple Interval Timer sells 4 one-off in-app purchases and Whistle Timer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Simple Interval Timer holds the better App Store score, 4.9 against 4.4. That said, the two scores are not equally well evidenced: Simple Interval Timer has 5.4K ratings behind it against 99, so its average is the more settled of the two. Written reviews point the same way: 85% of Simple Interval Timer's written reviews are positive against 29% of Whistle Timer's.

UpkeepUpdate frequency

Simple Interval Timer ships an update every 8 months, Whistle Timer every 10 months. The most recent releases landed on September 25, 2026 and September 15, 2026 respectively.

Scorecard4 real differences · 6 level
Simple Interval Timer versus Whistle Timer: the parameters behind the verdict, then further details
ParameterSimple Interval TimerWhistle Timer
PriceFreeFree
Rating4.9 (5.4K ratings) — better4.4 (99 ratings)
Positive reviews84.7% of reviews — better28.6% of reviews
Number of ratings5.4K — better99
Update frequencyEvery 8 months — betterEvery 10 months
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPod, Apple Watch — betteriPhone, iPod
Requires iOS14.5 — better15
Further details — not scored
Size10 MB4 MB
Age rating4++4
Developer0FFApplorium Ltd

Customer experience

Simple Interval Timer

All ratings5,444 ratings
Positive97.6%
Neutral1.2%
Negative1.2%
Written reviews398 reviews
Positive84.7%
Neutral4.5%
Negative10.8%

Whistle Timer

All ratings99 ratings
Positive82.8%
Neutral6.1%
Negative11.1%
Written reviews7 reviews
Positive28.6%
Neutral14.3%
Negative57.1%

Bugs and requests

Simple Interval Timer

Reported bugs

3 issues
  • Timer stops working when screen is locked
  • Countdown beeps not syncing with timer
  • Interval times not accurately tracked

Requested features

4 requests
  • Ability to name and delete saved configurations
  • More granular interval time settings (e.g., 1-second increments)
  • Stronger haptic feedback on Apple Watch
  • Integration with workout tracking apps

Whistle Timer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

4 purchases

Simple Interval Timer

One-time4
  • Espresso$0.99
  • Americano$1.99
  • Ad-free version$2.99
Show 1 more
  • Caramel Cappuccino$2.99
1 purchases

Whistle Timer

One-time1
  • Unlock all settings$2.99

Questions

Is Simple Interval Timer free?
Simple Interval Timer is free to download, with in-app purchases available.
Is Whistle Timer free?
Whistle Timer is free to download, with in-app purchases available.
Which has better reviews, Simple Interval Timer or Whistle Timer?
Simple Interval Timer is rated higher. Simple Interval Timer averages 4.9 out of 5 from 5.4K ratings, while Whistle Timer averages 4.4 from 99 ratings.
Do Simple Interval Timer or Whistle Timer have ads?
Simple Interval Timer shows ads; Whistle Timer does not.
Which is updated more often, Simple Interval Timer or Whistle Timer?
Simple Interval Timer ships an update every 8 months, and Whistle Timer every 10 months. Most recently, Simple Interval Timer was updated on September 25, 2026 and Whistle Timer on September 15, 2026.

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