Hold the plank.
Your voice runs the clock.
IsoTimer times your planks, deadhangs and wall sits — started and stopped by holding a single steady note. No reaching for your phone mid-hang. No cloud. No audio ever leaves your device.
Built for every isometric hold
Everything the timer should do — and nothing it shouldn't
A focused tool for tracking holds, not another bloated fitness app farming your data.
Voice start & stop
Hold one steady note — “aah” works well — and the clock starts. Make the same sound again to stop. Your hands stay on the bar where they belong.
100% on-device
A real-time DSP pipeline — pitch tracking, an adaptive noise floor, sustained-note detection — runs entirely on your phone. No servers, no API keys.
Per-user calibration
A quick one-time calibration learns the pitch you hold, so detection stays reliable in a noisy gym or a quiet living room.
Heart rate built in
Pair any standard Bluetooth monitor — Whoop broadcast, Polar, Garmin straps. Live bpm in the header; avg/min/max saved per hold.
Trends & records
Charts, sparklines and personal records for every activity, so you can actually see whether your hold is getting longer.
Backup & export
Full JSON backup that restores loss-free by merge, plus CSV export. Your training history is yours to move and keep.
From install to hands-free in three steps
Calibrate once
Run the short calibration — hold a vowel for a moment. IsoTimer learns the pitch of your voice and stores the profile on-device.
Get into position
Step up to the bar or drop into your plank. An optional 3–2–1 prep countdown gives you a moment to settle.
Run it hands-free
Hold your note — a chime confirms and the clock starts. Hold it again to stop. Your time and heart rate are saved to history automatically.
Your voice never leaves the phone
IsoTimer was built privacy-first. The microphone feeds an on-device signal-processing pipeline that works frame-by-frame in memory — and that is the entire data story.
- No audio is ever recorded to disk or transmitted.
- No cloud services, no accounts, no API keys, no tracking.
- Sessions, notes and heart-rate data stay in local storage.
- Backups only leave the device when you explicitly share them.
Everything that matters is free
The entire hands-free workflow is free, forever. Pro adds just two things — and it’s a one-time purchase, never a subscription.
- Hands-free voice start / stop
- Predefined holds — deadhangs, planks, wall sits
- On-device DSP — no audio leaves the phone
- 3·2·1 prep countdown
- Bluetooth heart-rate monitor
- Session notes, editing & undo
- CSV export + JSON backup / restore
No account, no ads, nothing gated.
- Custom activities
- History charts, trends & PR stats
Stop fumbling for your phone mid-hold.
IsoTimer is coming to iOS and Android. Hands-free, private, and focused.
Coming soon — no accounts, no subscriptions, no ads.