Comparison

Interval Flow vs Peaks

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

Head to head
About

Interval Flow

This app revolutionizes fitness routines with deep customization and advanced tracking for various activities like HIIT, Yoga, and CrossFit. It allows users to create, share, and follow personalized workouts with features like color-coded intervals, real-time progress tracking, and voice assistance.

Highlights
  • Color-coded intervals
  • Customizable circuits
  • Real-time progress tracking
  • Voice assist and search
  • Exercise library
  • Workout sharing
Features
Read full description

Interval Flow: Experience a Workout Revolution Interval Flow is your ultimate fitness companion, designed to transform your workout experience with deep customization and advanced tracking. This versatile app is perfect for a wide range of activities including HIIT, TABATA, CrossFit, Yoga, Pilates, Meditation, and more. With Interval Flow, you can stay focused on your fitness goals while the app handles the details. Key Features: - Color-Coded Intervals: Customize your workout visually with color-coded intervals. Set distinct colors for warm-ups, high-intensity bursts, rest periods, and more, to easily navigate through your routine. - Exercise Library: Build your workouts with ease! Add new exercises or select from the existing ones to tailor your workout to your specific needs. - Real-Time Progress Tracking: Keep a live tab on your workout progress. The dynamic interval list updates in real-time, ensuring you know exactly where you are in your routine. - Customizable Circuits: Create the perfect workout sequence by arranging various exercises into repeatable circuits tailored to your fitness level and goals. - Personalized Interval Warnings: Get timely alerts before an interval ends. Customize the warning sounds to suit your style, ensuring smooth transitions without missing a beat. - Interactive Workflow: Enjoy crafting your workouts with a user-friendly interface that’s as intuitive as it is functional. Setting up your ideal workout regime is now as engaging as the workout itself. - Voice Assist: Let our advanced voice assist guide you through your exercises, announcing what’s next so you can remain focused on your form and intensity. - Voice Search: Quickly find your favorite workouts using voice commands, making your preparation seamless and hands-free. - AirShare: Share your custom workouts with friends or clients effortlessly using AirDrop, enhancing connectivity and interaction. Why Choose Interval Flow? With Interval Flow, you don't just exercise, you experience a revolution in workout efficiency and enjoyment. The app’s intuitive interface and comprehensive customization options make it the optimal companion for anyone serious about fitness. Whether you're powering through a high-intensity session or seeking tranquility in yoga, Interval Flow adapts to your pace and preference. Unlock your potential with Interval Flow – where your workout meets innovation. Interval Flow Subscription: The app includes a 1 month long auto-renewable subscription with a 3-day free trial, which will unlock premium features, like unlimited workouts, timer program editing and autoplay and costs $4.99/ month. It will be charged to your credit card through your iTunes account and will automatically renew unless you canceled at least 24 hours before the end of the current period. Any unused portion of a free trial period will be forfeited when you purchase the subscription. Though your subscription for the current month cannot be canceled, you can turn auto-renewal off in your account settings after purchase. See the instructions here: https://support.apple.com/en-us/HT202039 You can read the terms of use and privacy policy here: https://kapi90.github.io/hiit_timer_privacy_policy.html End User License Agreement (EULA) of the App Store applies: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Peaks

This app analyzes your sleep patterns to predict your daily energy levels, helping you schedule tasks and breaks effectively. It uses scientific models to provide personalized energy curves and insights into sleep quality, recovery, and vitals.

Highlights
  • Personalized energy curve predictions
  • Sleep timing and debt tracking
  • Recovery and sleep score analysis
  • Home and Lock Screen widgets
  • Calendar export
  • Integrates with Apple HealthKit, Oura, Garmin
Features
Read full description

That afternoon crash isn't random: it's your rhythm. Peaks analyzes your sleep to predict exactly when you'll focus, fade, and recover, so you stop fighting your body and start working with it. No manual tracking required, if you already track sleep, you're ready. WHY PEAKS WORKS Most sleep apps show you what happened. Peaks shows you what to do about it. Your energy rises and falls in predictable waves driven by two systems: your circadian rhythm (your 24-hour internal clock) and sleep pressure (how long you've been awake). Peaks models both using the two-process model of sleep regulation, the same science behind NASA's astronaut protocols. The result: a personalized energy curve that updates every morning based on your actual sleep. WHAT PEAKS TRACKS Energy Peaks – See exactly when focus is highest. Schedule deep work and important tasks during these windows. Energy Dips – Know when crashes are coming before they hit. Plan breaks and lighter tasks accordingly. Sleep Timing – Track when your body releases melatonin so you know when to dim lights and wind down. Sleep Debt – Every missed hour accumulates. See your running total and how it clears over time. Recovery Score – HRV and heart rate analysis shows how ready you are for today. Updated every morning. Vitals – Watch for unusual heart rate patterns that might indicate your body is fighting something off. Sleep Score – Five components of sleep quality: duration, timing, efficiency, consistency, and debt impact. BUILT FOR YOUR WORKFLOW Widgets for Home Screen, Lock Screen, and StandBy, your rhythm at a glance Apple Watch app with complications for energy predictions Calendar export overlays peaks and dips on your schedule Shortcuts integration for custom automations Smart notifications for peaks, dips, and wind-down timing CONNECTS TO YOUR DATA Works with Apple Watch, Apple HealthKit, Oura Ring, and Garmin. No manual logging, if your sleep is tracked, Peaks uses it automatically. YOUR DATA STAYS YOURS All calculations happen on-device. No accounts, no servers, no third parties. Your health data never leaves your iPhone. Join 100,000+ people planning around their biology. ~ Flo & Clemens from Vienna Peaks is a wellness tool, not intended for medical diagnosis or treatment.

Screenshots

Interval Flow4 screens
Peaks4 screens

Verdict

The call

The clearest difference is monetization model: Peaks at freemium against Interval Flow's subscription. Peaks also leads on review sentiment (64% vs 48%). On price, rating, ratings volume and update cadence 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 Flow sells 10 in-app purchases, starting at $4.99 per 3 months and Peaks sells 6 in-app purchases, starting at $5.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Interval Flow against 4.7 for Peaks. Both are backed by a comparable volume of ratings — 167 and 289 respectively. Written reviews are what separate them: 48% of Interval Flow's written reviews are positive against 64% of Peaks's.

UpkeepUpdate frequency

Interval Flow ships an update fortnightly, Peaks every 2 weeks. The most recent releases landed on November 3, 2026 and November 12, 2026 respectively.

Scorecard2 real differences · 8 level
Interval Flow versus Peaks: the parameters behind the verdict, then further details
ParameterInterval FlowPeaks
PriceFreeFree
Rating4.7 (167 ratings) — better4.7 (289 ratings)
Positive reviews48.1% of reviews64.5% of reviews — better
Number of ratings167289 — better
Update frequencyFortnightlyEvery 2 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationSubscriptionFreemium — better
DevicesiPhone, iPadiPhone, iPad, Apple Watch — better
Requires iOS18.618.0 — better
Further details — not scored
Size20 MB232 MB
Age rating4+4+
DeveloperBence KaposztaVogelhaus Apps GmbH

Customer experience

Interval Flow

All ratings168 ratings
Positive93.5%
Neutral2.4%
Negative4.2%
Written reviews27 reviews
Positive48.1%
Neutral18.5%
Negative33.3%

Peaks

All ratings289 ratings
Positive92.4%
Neutral2.1%
Negative5.5%
Written reviews76 reviews
Positive64.5%
Neutral10.5%
Negative25.0%

Bugs and requests

Interval Flow

Reported bugs

10 issues
  • Programs deleted after update
  • App crashes when adding a program
  • Show/Hide Instructions adds time to interval
  • App defaults to unused workout
  • Cannot permanently skip to end of timed activity
Show 5 more
  • Intervals revert to previous settings
  • App won't remember order of custom circuit interval programs
  • Blank screen after download
  • Cannot get program to open
  • Cannot see bottom of screen on questionnaire

Requested features

5 requests
  • Increase repetitions to 20
  • Streamline adding intervals
  • Make it possible to hide unused workouts
  • Add music integration or option
  • Provide visual instructions for moves

Peaks

Not enough reviews yet to summarise bugs or requests.

In-app purchases

10 purchases

Interval Flow

Subscriptions8
  • 3 Month$4.993 Months
  • 1 Month$9.991 Month
  • 1 Month, 3 day trial3 Days trial$9.991 Month
Show 5 more
  • Annual7 Days trial$14.991 Year
  • 1 Year discounted$25.951 Year
  • 1 Year, 3 day trial3 Days trial$39.991 Year
  • 1 Year$39.991 Year
  • 1 Year Intro month1 Month trial$39.991 Year
One-time2
  • Free Lifetime subscriptionFree
  • Lifetime$24.99
6 purchases

Peaks

Subscriptions5
  • Monthly$5.991 Month
  • Yearly1 Year trial$39.991 Year
  • Yearly - Referral1 Month trial$39.991 Year
Show 2 more
  • Yearly - Referrer1 Year trial$39.991 Year
  • Yearly7 Days trial$39.991 Year
One-time1
  • Lifetime$149.99

Questions

Is Interval Flow free?
Interval Flow is free to download, with in-app purchases available.
Is Peaks free?
Peaks is free to download, with in-app purchases available.
Which has better reviews, Interval Flow or Peaks?
Interval Flow is rated higher. Interval Flow averages 4.7 out of 5 from 167 ratings, while Peaks averages 4.7 from 289 ratings.
Do Interval Flow or Peaks have ads?
Neither Interval Flow nor Peaks shows ads.
Which is updated more often, Interval Flow or Peaks?
Interval Flow ships an update fortnightly, and Peaks every 2 weeks. Most recently, Interval Flow was updated on November 3, 2026 and Peaks on November 12, 2026.

Other comparisons