Lock Screen
The Live Activity is the whole workout UI. Adjust weight or reps, tap ✓ — the rest timer starts right there.
Strength tracker for iOS
Log your lifts from the Lock Screen.
Never break your flow. Plan your program ahead, then log every set with a tap — phone in your pocket, chalk on your hands.
Bench Press
SET 2 / 4
80 kg × 8
Tap ✓ — the set logs and rest starts.
You never opened the app.
Friction-free logging
Four ways to log a set. None of them is “open the app.”
Your program is planned ahead, so mid-workout there’s only one job: confirm the set. Knurl puts that one tap wherever your eyes already are.
Dynamic Island
Your live set follows you anywhere in iOS. Long-press to expand, adjust, and log — then it tucks away again.
Home widget
Today’s session and your latest PR at a glance. One tap on ▶ and you’re warming up.
Apple Watch
The Digital Crown dials the weight — no keyboard. Heart rate flows straight to Apple Health while you train.
No calendar. Just your rotation.
Knurl proposes your next day. Life doesn’t break it.
Build your program once — Push, Pull, Legs, whatever your split is. Today shows the next day in your sequence, and only completing a workout advances it. Skip a Tuesday and nothing slides, nothing nags: the same day simply waits for you.
Rest is a choice, not a failure state.
Progressive overload, measured
Track what actually matters.
Every set you confirm feeds one question: are you getting stronger? Knurl charts your estimated 1RM and volume by body part, keeps a PR timeline per exercise, and measures your goals against lifts you’ve already logged — nothing to enter twice.
Private by design
No account. No server. Your training data never leaves your devices.
There is nothing to sign up for and nowhere for your data to go. Everything lives on your iPhone, synced through your own iCloud to your own devices. Export it as JSON or CSV any time — it’s yours.
On-device by default
Your iCloud, your sync
Full export, no lock-in
Optional · Start at the gym
Walk in. Start lifting.
Save your gym once and Knurl notices when you arrive. If a workout is due, a Live Activity offers to start it — one tap from the Lock Screen. Already trained, or it’s a rest day? It stays quiet. The geofence check runs entirely on your device.
Questions, answered.
When you start a workout, Knurl runs a Live Activity on your Lock Screen and in the Dynamic Island. Its buttons are real controls: adjust weight or reps with ±, tap ✓ to confirm the set. The set is saved, the rest timer starts, and the next set queues up — all without unlocking your phone.
No. Knurl has no accounts, no sign-in, and no server. You download it and start training. Your data belongs to your device and your iCloud — not to us.
Knurl syncs through your own iCloud, end to end. Your iPhone, Apple Watch, and any future devices signed into the same iCloud stay in step automatically. Turn iCloud off and everything simply stays local. You can export your full history as JSON or CSV at any time.
An optional feature: save your gym’s location once, and when you arrive with a workout due, a Live Activity offers to start it from your Lock Screen. The geofence check runs entirely on-device — your location is never sent anywhere. If you’ve already trained or it’s a rest day, Knurl stays quiet.
Set a target — a 1RM or a weight × reps — per exercise. Knurl measures it against the estimated 1RM from sets you’ve already logged, so progress tracks itself. No extra logging, no streaks, no guilt mechanics.
More questions? Visit support →