Holdfast: Freedive Trainer

Take a quick breath check and get CO₂ and O₂ tables built for you — free. Now with Apple Watch training, sharing, and a one-time Lifetime unlock.

Holdfast is a calm, focused breath-hold trainer for freedivers, spearos, and anyone learning to sit comfortably with the urge to breathe. Run proven CO₂ and O₂ tables on your iPhone — or entirely on your Apple Watch, screen-off and haptic-guided — so every session feels effortless.

WHY HOLDFAST

• CO₂ tables to blunt the urge to breathe; O₂ tables to extend your hold.
• Guided sessions with gentle haptic and audio cues — eyes closed, no screen needed.
• Built for Apple Watch: start, run, and finish a full session from your wrist, screen-off, driven by taps.
• Progress that motivates: history, streaks, personal bests, and clean charts.
• Heart rate during holds via Apple Health (optional).
• 100% offline. No account, no sign-up, ever.

FREE FOREVER

• The full CO₂ and O₂ table trainer, on iPhone and Apple Watch.
• Session history, streaks, and personal bests.

HOLDFAST PREMIUM

• Custom table builder — design your own ramps.
• Training plans — structured, progressive programs.
• Advanced analytics — deeper trends and recovery insight.

TRAIN SAFELY Holdfast is for dry training only. Never practice breath-holding in or near water alone, and never hyperventilate. Shallow-water blackout gives no warning. Stop immediately if you feel dizzy, lightheaded, or tingling, and talk to a doctor before starting breath-hold training if you have heart, lung, blood-pressure, or pregnancy concerns.

PRIVATE BY DESIGN Everything runs on your device. No account, no tracking; your health data stays in Apple Health.

— Holdfast Premium is an auto-renewing subscription.

• Monthly $3.99 / Annual $29.99, with a 7-day free trial (USD; prices vary by region).
• Payment is charged to your Apple ID at confirmation of purchase.
• It renews automatically unless auto-renew is turned off at least 24 hours before the end of the current period; your account is charged within 24 hours prior to renewal.
• Manage or cancel anytime in your App Store account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: [your privacy URL]