Your wrist is the
whole app.
Most apnea apps treat the watch as a remote. Holdfast runs the entire session from your wrist — screen dark, eyes closed, phone in another room. Just the haptics and your breath.
A rhythm you can feel.
Each phase has its own haptic signature — a soft swell to inhale, a steady pulse through the hold, a long release to exhale. Learn them once and you will never open your eyes mid-table.
Watch your tolerance grow.
Streaks, personal bests, and a max-hold trend that climbs week over week. Heart rate and mindful minutes sync to Apple Health automatically — no extra taps.
No account. No network. No tracking.
Every table, every chart, every setting works with airplane mode on. Nothing to sign up for, nothing leaves your device. Your training is yours.
Two tables, two adaptations.
CO₂ tables teach you to stay calm as the urge to breathe rises. O₂ tables stretch how long you can hold. Holdfast builds the ramp — you just breathe.
The hold stays the same length while rest shrinks each cycle. You start every hold with more CO₂ on board — and learn to stay relaxed through the urge to breathe.
Rest stays constant while the hold grows each cycle. You teach your body to do more with less oxygen — extending your comfortable maximum hold over time.
Free forever. Premium when you want more.
No ads. No dark patterns. The core trainer is free for good.
Never practice breath-holds in or near water alone — shallow-water blackout gives no warning. No hyperventilation. Stop immediately if you feel dizzy or unwell. Holdfast is a training aid, not a substitute for proper freediving instruction.