Ynter — Interval Timer

Ynter is a free interval timer that speaks the language of LLMs.

No subscriptions. No "Pro" tier. No locked screens. Every feature in Ynter is unlocked from the moment you install — including the ones below. If the app earns a spot in your week, an optional tip jar is how you say thanks. That's the whole business model.

Bring your own coach: any LLM
Ynter reads a simple JSON lesson format. That means you can ask ChatGPT, Claude, Gemini, or any other model to design a workout for you — "give me a 25-minute kettlebell EMOM for shoulders," "build me a beginner yoga flow with long holds" — copy the result, paste it into Ynter, and run it. Your training plans live with you, not behind someone's API key.

There's a built-in import sheet with the prompt format ready to go. Hand it to your LLM of choice and you have a tailored workout in under a minute.

Built-in lessons to start with
Don't want to prompt anything? Ynter ships with ready-to-run routines:
• HIIT & Tabata — 45/15, 20/10, classic intervals
• Yoga flows — long holds with gentle pacing
• Strength sets — work, rest, rounds, done
• Quick warm-ups — six minutes when that's all you've got

A real editor for custom workouts
Prefer to build by hand? The lesson editor lets you set every step's name, work time, rest time, and rounds. Tap any duration to type an exact value on the number pad. Save it, run it, share it.

Reps for strength and machine work
Not everything is a countdown. Switch a step to reps and Ynter drops the work timer — do the set at your own pace and tap "Done" when you're finished. Only the rest is timed. Perfect for the weight room, on iPhone and Apple Watch.

Edit with Apple Intelligence
On devices with Apple Intelligence, rewrite a lesson right in the editor: "double all rests," "add a cool-down," "turn this into a 20-minute session." The on-device model rewrites the lesson privately and offline — nothing leaves your device — and you review the result before saving.

Live Activity & Dynamic Island
Glance at your phone face-down on the bench: current interval, round, and time remaining sit right on the Lock Screen and in the Dynamic Island. No unlock needed.

Apple Watch app, included
Lessons sync to your wrist. Haptics fire on the Watch. Sessions keep running even if your phone is across the room.

iCloud sync across every device
Build a lesson on your Mac, run it on your iPhone, finish it on your Watch. Same routines, every screen.

Voice cues that respect your music
Spoken countdowns ride along on top of whatever you're listening to instead of cutting it. Mute the voice and you still get a bell and a haptic tap. Premium voices supported when installed.

iPhone, iPad, Mac, and Apple Watch
Built in SwiftUI for every Apple platform you own.

What you get — all free:
• Paste-in JSON lesson import (works great with any LLM)
• Built-in HIIT, Tabata, yoga, and strength lessons
• Custom lesson editor with work/rest/rounds — plus rep-based steps and exact number-pad entry
• Apple Intelligence lesson editing (on supported devices)
• Live Activity & Dynamic Island
• Apple Watch app with haptics
• iCloud sync across iPhone, iPad, Mac, and Watch
• Spoken interval cues with music ducking
• Background audio
• No ads. No tracking. No subscriptions. No paywalled features.

Optional tip jar if you want to support development.

Get the workout your AI just designed. Ynter will count.