RUN interval vs Kronos Studio
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RUN interval
This app simplifies interval and Fartlek running by allowing you to set custom targets for time or distance during hard, easy, and rest efforts. It offers detailed post-run summaries, audio and visual feedback, and an Apple Watch app for enhanced training.
- Customizable interval sessions
- Time and distance targets
- Distance Goal option
- Audio and visual feedback
- Detailed run summaries
- Apple Watch app
- Strava sharing
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Easily set up and record your Interval and Fartlek running sessions. With the flexibility of using time and/or distance as interval targets for your "Hard", "Easy" and "Rest" efforts. The simple but highly configurable interface on your phone and watch will have you running sooner. Now with a Distance Goal option for your session. Along with great audio and visual feedback, detailed post-run summary, share your runs to Strava, and a full-featured Apple Watch app. You can also record your regular runs with voice-over calling out distance and pace feedback. Key Features: • Easily create flexible custom interval sessions. • Utilize three effort targets "Hard", "Easy" and "Rest" in each set, targeting time or distance (meters or miles). • You can "Skip" any of the three efforts to create flexible sets, like building a progressive intervals session. • NEW: Set a Distance Goal for your session, that repeats the sets from the start until the distance has been reached. • Set a Warm-Up and Warm-Down timer or distance around your session. • Clear and easily glanceable visuals and audio prompts, including vibrations. • Voice-over prompts to save you from looking at the screen, great for iPhone or headphone users. • Voice-over prompts include the upcoming intervals effort and time/distance amount, and your last intervals average pace and heart rate. • Full-featured Apple Watch App! • Heart Rate Zones! (see description below) • Indoor Mode, no GPS, for treadmill running. • Sound Mode, for normal, discrete or silent audio prompts on your watch. • Vibration feedback on both the phone and watch. • Detailed run summary, showing pace for hard and easy efforts. • The run summary also includes interval breakdown, distance breakdown and heart rate details. • Play music or podcasts while running and still hear the audio prompts. • Sharing. Share a summary photo with your friends. • Private data. We don’t send any of your data to a server or share it with anyone. Session Types: • Normal Run – Record a normal run, long or short. • Record Intervals – If you run with a group or do an undefined session, then use the Record Interval option. It allows you to manually change between "Hard" and "Easy" reps, allowing you to record your session. • Custom Intervals – Our fully flexible intervals that allow you to use time and/or distance for the efforts. Add multiple intervals sets together to create the session you want. Sharing: From the summary screen, you can share your runs with friends or across social media. If you want to share directly with friends or across other social media, you can share a summary image with the details of your run. Heart Rate Zones: (Apple Watch Only) Zones are displayed as grouped percentages of your maximum heart rate. Giving you an indication of your current work rate based on your current heart rate. Just enter your maximum workout heart rate into our Settings screen and they will display on your Watch the next time you run. Zone 1: Very Light Effort 50-60% (Gray) Zone 2: Light Effort 60-70% (Blue) Zone 3: Moderate Effort 70-80% (Green) Zone 4: Hard Effort 80-90% (Yellow) Zone 5: Maximum Effort 90-100% (Red) Privacy: We don’t want to know where you have run, that's for you to worry about. We don’t send any of your data to a server or share it with anyone you don't want too. We keep your running records safe in Apple Health so you have control. Apple Heath gives you the control over who accesses your data. We only write and read the data we record from your running. Feedback: And because we don't send any data to a server, we need you to send us feedback and suggestions. Hit the Support link below or visit our website to contact us.
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.
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Verdict
The clearest difference is update cadence: Kronos Studio at every 2 days against RUN interval's every 3 months. 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. RUN interval sells 2 one-off in-app purchases 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.
RUN interval ships an update every 3 months, Kronos Studio every 2 days. The most recent releases landed on October 12, 2026 and October 1, 2026 respectively.
| Parameter | RUN interval | Kronos Studio |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (1K ratings) — better | — |
| Positive reviews | 77.5% of reviews | — |
| Number of ratings | 1K — better | — |
| Update frequency | Every 3 months | Every 2 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, Apple Watch |
| Requires iOS | 15.6 — better | 16.4 |
| Further details — not scored | ||
| Size | 34 MB | 97 MB |
| Age rating | 4+ | 12+ |
| Developer | CAN YOU HEAR ME SOFTWARE | Muller Labs LLC |
In-app purchases
RUN interval
- The full RUN interval$1.99
- The full RUN interval$3.99
Kronos Studio
- Kronos Pro Monthly$8.991 Month
- Kronos Pro Yearly$49.991 Year
Questions
Is RUN interval free?
Is Kronos Studio free?
Do RUN interval or Kronos Studio have ads?
Which is updated more often, RUN interval or Kronos Studio?
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