Interval training for your Apple Watch

SILO uses the Taptic Engine on the Apple Watch to alert you between intervals. Do your HIIT workouts without having to watch the clock or disturb others nearby.

Easy Setup
Simply set up your workouts on your iPhone. When you're ready, just pull up Apple Watch and press "GO". A tap on the wrist cues you at each interval. During your workout, glance at the watch for status and to preview the next activity.

Airplane Mode
For best results, turn on airplane mode right from your Watch. This lets you avoid false positive haptics during your workout.

Simple Stats
At the end of a workout session, SILO connects with HealthKit and displays your heart rate, calories burned, and workout time.

Fully Customizable
Add up to three Presets from your phone right to your watch. On the iPhone, set up your interval activities and the number of rounds. You can edit the names of the presets and the activities – hit Sync and you're all set.

HIIT, CrossFit, Circuit Training, Tabata
Works with these and more workouts that require precise timing for intense bursts of exercise followed by recovery periods.

All these and more make SILO |trainer| the perfect workout companion for your wrist.

• Haptic notifications between workout intervals
• iPhone not needed during workout
• Integrated with Health Activity Rings
• Post-workout heart rate monitor
• Post-workout calorie count (Move goal)
• Simple setup (set and forget)
• Preview the next activity
• Three customizable presets
• Rearrange presets by hold & drag
• Up to 12 Activities per workout and up to 30 rounds
• Rearrange activities or presets by hold & drag
• Delete activities by swipe left
• Workout in airplane mode to avoid distractions
• 3, 2, 1 countdown

The vision for SILO is to give you the ultimate workout experience. With your support, I'll continue to refine and maintain simple design. Learn more at

*Apple Watch Required

What’s New

Version 1.1.6

Optimized for iPhone X

- Haptics between intervals are more noticeable
- Added 3,2,1 countdown before workout

Check out the new support page:

Ratings and Reviews

4.0 out of 5
3 Ratings

3 Ratings

AdeTheCrafter ,

Solid Interval Timer

Silently taps me on the wrist during workouts, just what I needed! I've searched the app store left and right, and this is the best (if not only) HIIT timer for the Apple Watch, that actually works right. What I love the most is it's simple and non-cluttered like the other stuff. This app has one job and it does it well, and then some!

y_k_s ,

Haptic feedback won't work

... whenever screen goes off. I wanted to use this for doing a set of streching excercise but that makes it the app practically unusable.


Omar Hijaz
36.3 MB
Health & Fitness

Requires iOS 9.0 or later. Compatible with iPhone and iPod touch.



Age Rating
Rated 4+
© 2017 dark matter developers


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