Comparison

IntervalFree vs Kronos Studio

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

Head to head
About

IntervalFree

This app provides a simple and fully customizable interval timer for workouts. It offers unlimited workout profiles, background support, and Live Activities for real-time progress tracking on your lock screen. Enjoy a completely free experience with no ads or paywalls.

Highlights
  • Unlimited workout profiles
  • Customizable action/break durations
  • Live Activities on Lock Screen
  • Background timer support
  • Multiple sound themes
  • Workout library with stats
  • Celebration screen upon completion
Features
Read full description

IntervalFree is the workout interval timer that's actually free. No paywalls. No ads. No tricks. Every feature is unlocked from day one — and stays that way forever. SET UP IN SECONDS Configure your action duration, break duration, and number of sets with intuitive scroll pickers. Tap Start and your profile is saved automatically. No account required. GO CUSTOM: BUILD ROUTINES BLOCK BY BLOCK Need more than one interval pattern in a session? Switch to Custom mode and build your routine block by block — a warm-up, a legs circuit, an abs finisher — each with its own action time, rest time, and number of rounds. Add a breather between blocks or keep it rolling; the whole session runs as one seamless timer. Prefer things simple? Simple mode hasn't changed at all. You'll never have to touch Custom, and everything you've already saved looks and behaves exactly as before. GLANCEABLE & MULTITASK-READY A large timer ring shows your remaining time at a glance—green for action, blue for break. With Live Activities, your progress stays visible right on your Lock Screen or Dynamic Island. Switch apps or lock your phone with confidence; the timer runs perfectly in the background. YOUR SOUND, YOUR PACE Choose from multiple Sound Themes to match your workout vibe. High-fidelity audio alerts keep you on pace even when your phone is in your pocket, and our smart audio handling ensures your music stays clear while the timer beeps. SAVE UNLIMITED WORKOUT PROFILES — NOW PROTECTED Create as many workout profiles as you need. Name each one, pick from 20+ activity icons (running, swimming, yoga, boxing, and more), and choose from 10 colors. Every profile is instantly recognizable in your workout library. Your saved presets are now protected: the settings can't be changed by accident — tap Edit first. Your edits are kept when you tap Save Preset, or when you start the workout. YOUR WORKOUT LIBRARY See how many times you've started and finished each workout. Tap any profile to load it instantly—no re-entering settings every time. Quick-start chips let you jump into your most-used routines in one tap. CELEBRATE EVERY WIN Every completed workout gets a celebration screen with your stats, a trumpet fanfare, and a fun animated surprise to keep you motivated. FULLY CUSTOMIZABLE • Custom mode: multi-block routines with per-block intervals • Protected presets: no more accidental overwrites • Background Support: Use other apps while you train • Live Activities: Real-time progress on your Lock Screen • Sound Themes: Multiple audio styles to choose from • Adjustable action and break durations (seconds to minutes) • 1 to 99 sets per workout • 20+ workout icons & 10 profile colors • Profiles auto-save on start WHY INTERVALFREE? We were tired of interval timer apps that lock basic features behind subscriptions. So we built one that gives you everything—for free. No premium tiers. No "free trial" that expires. No data sold to advertisers. IntervalFree is maintained by a small team who believes great tools should be free. If it becomes part of your routine, you can support us with a voluntary coffee—but there's absolutely no pressure. Perfect for HIIT, Tabata, circuit training, boxing rounds, stretching, meditation, or any activity that uses timed intervals. Requires iOS 17.0 or later. Works on iPhone and iPad.

About

Kronos Studio

Features
Read full description

Real strength workouts, written for the gear you've got and the 30 minutes you have. Works with ChatGPT and Claude. Open Kronos and today's session is ready: exercises, sets and the weights filled in, built for the equipment in front of you and the minutes you named. Different every time, shaped to your gear, your time, and how you actually feel today. You don't need more motivation. You need fewer decisions. IT ALREADY KNOWS • It already knows what's at your gym. • It already knows you only have 20 minutes. • It already knows you skipped Tuesday. • It already knows you hated lunges last time. • It already knows you've done legs twice this week. So you don't have to. HOW ONE TAP WORKS BUILT AROUND YOUR ACTUAL GEAR. A pair of dumbbells, a full gym, or nothing at all: tell Kronos what you have and it never writes a workout that needs a cable machine someone else is on. It fills in the weight, too, instead of leaving you a blank. HOTEL ROOM? HOTEL WORKOUT. Save your spots: gym, home, hotel, the park. Switch in one tap and the workout reshapes itself. Flag an injury once and it plans around that too. SWIPE EXERCISES, NOT EX'S. Love it, like it, meh, never again. Every swipe trains the next workout. YOUR WHOLE WEEK, IN ONE PLAN. Import a plan, ask your AI for one, or let Kronos build it. Every session sits in one week beside your own timers. Set a focus for a day, steer the week in your own words, and a missed session drops off with nothing owed. YOUR AI COACHES. KRONOS TRAINS. Ask ChatGPT or Claude for a workout or a plan. Check the preview, save it, and it lands in Kronos, ready to run on your phone with set logging. Your first AI-sent workout runs free. Got one already? Paste it, or snap a photo. TRAIN WITH YOUR CREW Start a challenge, drop the code in the group chat, and every finished day puts your name on the Wall beside theirs. Pick a shape: a daily target, a ladder, a weekly max test, or just show up. Wildcards cover a missed day, streaks carry, and nobody gets a notification about your rest day. It's the part that makes people keep going, and it isn't a leaderboard for strangers. It's five people you already know. A BIG CALM TIMER We tell you what's next; you just lift. No tapping mid-set. Benchmarks are in there too. Cindy, Murph, and 42 more, each one scaled to the kit you actually own instead of the kit the workout assumed. LOGGING, WHEN YOU WANT IT Log a set if you want the number. Skip it if you don't. Your week, your lifts, and your history are there when you go looking, and never the price of getting a workout. PLUS A FREE INTERVAL TIMER. ACTUALLY FREE. HIIT, Tabata, EMOM, AMRAP, plus full custom intervals. Save unlimited presets. Cues over your music, on your lock screen and in 9 languages. No ads, no run limits. Free forever. Try it without an account. Pro when you want a coach in it: Kronos fills your timer with real exercises for the kit you have. WHAT WE BELIEVE Variety beats optimization. Constraints are features. Decisions are willpower taxes. Today's mood matters. Adherence beats intensity. Fun is a strategy. A B+ workout four days a week beats an A+ workout once. Every time. KRONOS PRO Free is the interval timer, forever. A free account also builds and imports plans, runs your own timers from your week, logs your sets and joins challenges. Pro runs every session Kronos writes or reads in, scores your whole history and adds crew insights. Prices are shown in the app and may vary by region. Subscriptions auto-renew unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in your App Store account settings. Terms: https://getkronos.app/terms Privacy: https://getkronos.app/privacy Most fitness apps make you a workout plan. Kronos makes you a person who works out.

Screenshots

IntervalFree4 screens
Kronos Studio4 screens

Verdict

The call

The clearest difference is in-app purchases: IntervalFree at none against Kronos Studio's 2. Kronos Studio's advantage is update cadence (every 3 days vs every 2 months) and device support (3 vs 1). On price, ads and iOS requirement 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. Kronos Studio sells 2 in-app purchases, starting at $8.99 per month. IntervalFree asks for nothing beyond the download.

UpkeepUpdate frequency

IntervalFree ships an update every 2 months, Kronos Studio every 3 days. Both last shipped on November 5, 2026.

Scorecard3 real differences · 7 level
IntervalFree versus Kronos Studio: the parameters behind the verdict, then further details
ParameterIntervalFreeKronos Studio
PriceFreeFree
Rating4.9 (40 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings40 — better—
Update frequencyEvery 2 monthsEvery 3 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhoneiPhone, iPad, Apple Watch — better
Requires iOS17.016.4 — better
Further details — not scored
Size8 MB102 MB
Age rating4+12+
DeveloperLIFEFLOW AI, LLCMuller Labs LLC

In-app purchases

None

IntervalFree

No in-app purchases

2 purchases

Kronos Studio

Subscriptions2
  • Kronos Pro Monthly$8.991 Month
  • Kronos Pro Yearly14 Days trial$49.991 Year

Questions

Is IntervalFree free?
IntervalFree is free to download, with no in-app purchases.
Is Kronos Studio free?
Kronos Studio is free to download, with in-app purchases available.
Do IntervalFree or Kronos Studio have ads?
Neither IntervalFree nor Kronos Studio shows ads.
Which is updated more often, IntervalFree or Kronos Studio?
IntervalFree ships an update every 2 months, and Kronos Studio every 3 days. Most recently, IntervalFree was updated on November 5, 2026 and Kronos Studio on November 5, 2026.

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