LockIN
Run smarter. Stay locked in.
A Zone 2–first running coach for iPhone and Apple Watch. LockIN finds your easy-effort heart-rate band, then keeps you inside it — so the runs that are supposed to be easy finally are.
The easy band that builds the engine — most of your week belongs here.
Mostly easy, a little hard. Your plan holds the ratio so you don’t have to.
No servers, no accounts on our side. Your health data never leaves your phone.
Your band is a box.
Stay inside it.
The brackets are your target zone. The line is your heart rate arriving from the left, and the big number rides its tip — so its height tells you where you are before you’ve read a single digit. Inside the box, everything is lime. Drift out and the line recolors; go well over and the whole screen tells you to walk it back. It’s all on your wrist, so your phone stays in your pocket.
A week that
adapts to you.
Pick a goal — 5K to marathon, or just a stronger base — and LockIN builds the week around it, holding the easy-to-hard ratio. Three taps after each run tell it how you slept, how sore you are, and how it felt. When the next long run is too big a jump, it says so, and eases it.
Scored in minutes,
not pace.
Easy runs don’t look impressive on a pace chart, which is exactly why people abandon them. So LockIN counts what actually builds fitness: minutes spent in your zone, week over week, with your real easy-to-hard split alongside.
Built for the easy days.
The Line
Your live heart rate drawn against your target band, so trend is obvious at a glance.
Voice & haptics
A spoken cue and a directional tap when you drift — not a screen you have to watch.
Adaptive 80/20
Plans for 5K through marathon that adjust to how your runs actually felt.
Apple Watch
A full watch app with its own workout session, mirroring live to your iPhone.
Music that yields
Apple Music plays on, ducking politely under every coaching cue.
Zone calibration
Three ways to find your band — field test, heart-rate reserve, or age-based — with manual override.
The whole run.
Today's run
This week's plan
Minutes in zone, by week
Every run, mapped by effort
It stays on your phone.
No servers. LockIN has no backend. Your runs, routes, and heart rate are stored on your device and in Apple Health.
No analytics, no tracking. No third-party SDKs, no advertising, no cross-app tracking.
AI runs locally. Playlists are drafted on-device with Apple Intelligence — only music searches reach Apple Music.
Location is optional. Coaching works without it; routes are saved only on your device.
Your easy runs,
finally easy.
LockIN is free on iPhone and Apple Watch. Heart-rate coaching, plans, and progress are all included.