FastFlex is an intermittent fasting timer designed to respect you. Every fasting protocol stays free forever, the coach voice is encouraging (and dial-down-able), and your data stays on your phone.

This app is not a medical device and does not diagnose, treat, cure, or prevent any condition. FastFlex provides general educational content about intermittent fasting. Consult a qualified healthcare provider before starting any fasting regimen, especially if you are pregnant, breastfeeding, under 18, or have a medical condition.

GROUNDED IN RESEARCH
FastFlex is built on a review of 40+ scientific sources on fasting metabolism, ketosis, and time-restricted eating. The metabolic phases and the Cell Repair Score are honest, estimated proxies based on that evidence, not measured medical readings.

WHY FASTFLEX
- All fasting protocols are free, forever. No protocol is ever paywalled, including the full custom-plan builder.
- Personalised to you. Your metabolic phase timings adapt to your carb intake, activity, age, and gender, so the phases reflect your body rather than a generic chart.
- No paywall in onboarding, no nagging.
- Local-first by design. Your fasting history and settings live only on your device. We collect no personal data and have no servers.
- Calm, modern design. The timer is sacred.

FEATURES
- Beautiful live timer with a progress ring and projected end time.
- Personalised Phase Lanes: watch yourself move through Digesting, Sugar-burning, Fat-burning, Ketosis, and Autophagy, with thresholds tuned to you. Tap any phase to learn what is happening in your body.
- Cell Repair Score: an honest, estimated A-F signal of how strong and consistent your fasting practice is, with a clear explainer of what it means and how to optimise it.
- Repair and energy section: see the energy you burn during a fast and a smoothed weight trend over time, with honest insights and no food logging required. Movement from steps and quick logged exercises (push-ups, squats, stretching) pulls your phase lines earlier.
- Optional pre-fast check-in: a two-tap log of carbs, sleep, stress, and body metrics that personalises your score and tracks outcomes over time.
- Plans built in: 16:8, 14:10, 18:6, 20:4, OMAD, longer fasts (24h, 30h, 36h), an open-ended option, plus a full custom-plan builder.
- Optional reminders: a gentle alert when your fast completes, plus opt-in metabolic-milestone and long-fast check-in notifications. You choose what fires.
- Editable fast records and a friendly result screen. Forgot to start the timer? Adjust it. Ended early? "Kind work for showing up." Then Edit or Resume.
- Real Calendar of your fasts: view, edit, add a past fast you did off-app.
- Real Trends: best streak, completion %, averages, weekly deep-fast time, your weight trend, and your Cell Repair Score over time.
- Coach tab: bite-sized education and research-backed picks (clearly tagged Fasting-safe vs Eating-window).
- Forgiving streaks. A missed day never erases your best run.
- Coach dial: Full / Light / Off. Encouragement is yours to control.
- Light, Dark, or System theme.
- Accessibility-first: semantic labels, reduced-motion support, screen-reader friendly.