JTervals
Simple HIIT & Interval Timer
Only for Watch
Free
Apple Watch
No subs, no ads, no sign-ups. Set your work and rest times, or a target pace for a run, and train. Taps and beeps keep you on track so you never need to check your wrist.
JTervals is a simple, no-frills interval and paced-run timer for Apple Watch. Set your active and rest times, or a target pace, press Start, and let your wrist tell you when to go, when to ease off and when to speed up.
THREE MODES
• Intervals – set your active and rest times and a total time. JTervals works out how many sets fit and counts them down for you. Set the total to 0 to keep going until you stop.
• Trainer – set active, rest, sets per group, a longer rest between groups, and the number of groups. Made for circuits at home or in the gym: one group per exercise, indoors, no map.
• Paced – set a run or walk length (or 0 for open-ended), a target pace per mile or kilometre, and how much leeway you allow either side. JTervals watches your pace over the last minute and, once a minute, taps you if you're too fast or too slow.
RUN AT YOUR PACE
In Paced mode the screen says ON PACE, TOO FAST or SPEED UP under your target, with your current pace, the distance so far and the pace of your last minute. Quick heavy taps and beeps mean ease off; slow rising ones mean pick it up, so you can tell them apart without looking. Change the target, or the leeway either side of it, mid-workout with a swipe. Miles or kilometres, your choice. Afterwards, your splits and every minute's pace are listed on the watch and kept in its log.
WARM UP, WORK, COOL DOWN
Every workout can begin with a warm-up and end with a cool-down, each as long as you like or switched off. A 5-second countdown leads into the first set. Skip the warm-up when you're already warm, and start the cool-down early when you've had enough.
TRAIN WITHOUT LOOKING
Every change – go, rest, group rest, cool-down, done, too fast, speed up – has its own haptic tap and beep, and the last five seconds of each phase count down on your wrist. Switch on Voice and your watch says each set, rest and cool-down as it starts, and in Paced mode your pace and on pace, speed up or slow down once a minute, and each mile or kilometre as you pass it. Choose a female or male voice, lifted by Louder voice to cut through street noise. Beeps and voice play through the watch speaker or headphones connected to your watch, dip your music while they play, and sound even when your watch is in Silent Mode. Prefer just the taps? Switch the beeps off and pick light, normal or strong taps, in Settings or in the middle of a workout. Try buttons let you feel and hear your choices before you set off.
BIG NUMBERS
The timer is big and colour-coded by phase, so a glance is enough. In Intervals your distance so far sits beside the set count. Want your heart rate, your set count, your distance or the time left? Tap it and it fills the screen for a few seconds.
IN CONTROL
Pause, resume or stop with one swipe, and change the taps, the voice or your pace target without leaving the workout. When you finish, choose to save the workout or discard it.
YOUR LOG
Every workout you save is kept in a log on the watch: time, sets, distance, calories and heart rate, and for Paced runs the target, your splits and the pace of every minute. Open one to share it as text or delete it.
WORKS WITH APPLE HEALTH
Saved Intervals and Paced workouts go into Apple Health as Outdoor Runs, with your heart rate, active calories, distance and GPS route; Trainer sessions are saved as indoor HIIT. They count toward your Activity rings and show up in the Fitness app, route on the map and all, even if you trained without your iPhone nearby.
PRIVATE BY DESIGN
No accounts, no ads, no tracking. Your workout data and your routes stay in Apple Health on your devices.
JTervals is free.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Jonathan Parkins, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Jonathan Parkins
- Size
- 1.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Apple Watch
Requires watchOS 11.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © JonnyP Industries LTD 2026