Seconds Interval Timer vs Kronos Studio
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Seconds Interval Timer
This app provides a versatile interval timer for various workout types like Tabata, HIIT, and circuit training. It features a clear, full-screen display, customizable alerts, and background operation. Users can also utilize a stopwatch and countdown timer, with integration for Apple Health.
- Full-screen colored display
- Templates for HIIT, Tabata, Circuit Training
- Voice and audio alerts
- Music assignment per interval
- Background operation
- Apple Health integration
- Stopwatch and countdown timer
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Seconds is an interval timer for HIIT, Tabata, EMOM, circuits and any workout built from timed intervals. It calls each interval out loud, keeps running with the screen off, and runs on iPhone, iPad and Apple Watch. Apple has featured it, and Joe Wicks, The Body Coach, has said it is the fitness app he uses more than any other. BUILD ANY WORKOUT - Start from a HIIT, Tabata or circuit template, or build a timer from scratch with sets, rounds and intervals of different lengths. - Chain timers into one compound timer, so a warm-up flows into the main set and then a cool-down. - Color-code every interval so you know what is coming before the beep. - Share a timer with a friend in one tap. HEAR IT, DON'T WATCH IT - Voice cues call out each interval by name and warn you before the next one starts. - Beeps and bells are there too if you would rather not be talked at. - Play your own music, per timer or per interval. Cues duck the music and it comes back up when they are done. - The timer keeps going in the background while you use other apps or the screen sleeps. ON THE GYM FLOOR - A full-screen, color-coded display you can read from across the room, in portrait or landscape. On iPad it uses the whole screen. - A lock button stops a stray tap from pausing your set. APPLE WATCH - Seconds runs on the watch by itself, so the phone can stay in the locker. Timers you build on the phone sync to the wrist, and Quick Intervals builds a basic circuit on the watch itself. MORE TIMERS - A stopwatch that marks your best and worst laps. - A countdown timer with five preset durations (three on Apple Watch). APPLE HEALTH - Save workouts and mindful sessions to Health. With a heart rate monitor connected, Seconds reads your body measurements and year of birth from Health to estimate calories burned. FREE TO TRY, ONE PAYMENT TO UNLOCK - Everything is available from the first launch. Build any timer and run it. - Each timer locks after you run it once. A single in-app purchase removes the lock on every timer you make. SECONDS AND SECONDS PRO - Seconds Pro is the same app, paid once up front, with nothing to unlock. The two are separate products and a purchase in one does not carry over to the other. If you bought Seconds Pro, download Seconds Pro. If you bought the unlock in Seconds, download Seconds and use Restore Purchases.
Kronos Studio
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Real strength workouts, written for the gear you've got and the 30 minutes you have. 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. PROGRAMS THAT BEND. Seventeen programs, 2 to 8 weeks each, written for your gear and shaped to your week instead of the other way round. The first session of every one is free. Any day you'd rather not be on one, build a single session instead. 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. Then swipe: right to keep, left for never again. 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. The screen stays awake, the cues mix over your music, and there are no ads. No account needed, no "Pro timer" upsell. Not now, not ever. 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, plus five workouts written for your gear and the first session of every program. Pro is the rest: a new workout every day you open the app, every session of all 17 programs, your whole history scored, up to 10 challenges at once, and 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. The best workout is the one you'll actually do.
Screenshots
Verdict
The clearest difference is update cadence: Kronos Studio at every 2 days against Seconds Interval Timer's monthly. Kronos Studio also leads on iOS requirement (16.4 vs 18.0). On price, ads, in-app purchases and device support 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
Both are free to download. Seconds Interval Timer sells 1 one-off in-app purchase and Kronos Studio sells 2 in-app purchases, starting at $8.99 per month. Whichever you choose, the download price is not the number that matters.
Seconds Interval Timer ships an update monthly, Kronos Studio every 2 days. The most recent releases landed on October 13, 2026 and October 1, 2026 respectively.
| Parameter | Seconds Interval Timer | Kronos Studio |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (24K ratings) — better | — |
| Positive reviews | 74.6% of reviews | — |
| Number of ratings | 24K — better | — |
| Update frequency | Monthly | Every 2 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, Apple Watch |
| Requires iOS | 18.0 | 16.4 — better |
| Further details — not scored | ||
| Size | 95 MB | 97 MB |
| Age rating | 4+ | 12+ |
| Developer | Runloop Ltd | Muller Labs LLC |
Bugs and requests
Seconds Interval Timer
Reported bugs
2 issues- Timer sometimes stops working unexpectedly
- Issues with restoring purchases on new devices
Requested features
5 requests- Ability to change beep/alert volume independently
- Option to delay transition between intervals
- Sync workouts across devices
- More preset workout templates
- Heart rate monitoring integration
Kronos Studio
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Seconds Interval Timer
- Advanced Version$7.99
Kronos Studio
- Kronos Pro Monthly$8.991 Month
- Kronos Pro Yearly$49.991 Year
Questions
Is Seconds Interval Timer free?
Is Kronos Studio free?
Do Seconds Interval Timer or Kronos Studio have ads?
Which is updated more often, Seconds Interval Timer or Kronos Studio?
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