# Cardia Fast — Circadian Fasting Tracker

> Circadian Fasting Tracker (iPhone/iPad app by Tuong Nguyen.)

- Source: https://appshunter.io/ios/app/cardia-fast/id6759427127 (this page in markdown: same URL + `.md`)
- Developer: [Tuong Nguyen](https://appshunter.io/developer/1878188325)
- Category: Health & Fitness
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 3 MB
- Languages: American English
- Released: 2026-02-25
- Data updated: 2026-06-21
- User reviews in markdown: https://appshunter.io/ios/app/cardia-fast/id6759427127/reviews.md

## What is Cardia Fast?

**Cardia Fast** turns intermittent fasting into metabolic science. Track your fasts through 5 research-backed zones, align with your circadian rhythm using sunset detection, and learn what's happening in your body at every stage.

**Solar Dial Timer**
A beautiful 24-hour ring shows your fasting progress in real time. Watch your zone change from Fed → Fat Burning → Ketosis → Autophagy → Deep Autophagy as your fast progresses.

**5 Metabolic Zones**
Not all fasting hours are equal. Cardia Fast tracks the metabolic stage of every fast — so you know exactly when your body starts burning fat, entering ketosis, and triggering autophagy.

**Circadian Mode**
Fast with the sun. Enable sunset-aware fasting and let Cardia Fast calculate your optimal eating window based on your local sunset time — the way your body was designed to eat.

**Morning Debrief**
Start each day with a personalized summary — your streak, last fast duration, zone reached, and a motivational message to keep you going.

**Fasting Score**
Get a weekly score (0–100) based on consistency, duration, and depth. See exactly where you're excelling and where you can improve.

**12 Achievement Badges**
Unlock milestones like First Fast, Week Warrior, Fat Burner, Autophagy Ace, and more. Track your progress without cartoon gimmicks.

**PRO FEATURES**
Unlock Circadian Coach tips, pattern analysis, weight correlation charts, weekly summaries, micro-journaling, vacation mode, and data export — all with a single subscription.

**CARDIA COMPLETE**
Access all Cardia apps with a single subscription — Heart, Mind, Sleep, Steps, Hydrate, Fast, and more. One ecosystem for your complete wellness journey.

**PRIVACY FIRST**
All health data stays on your device. No accounts required. No data leaves your phone.

Download Cardia Fast and start fasting with the science.

Terms of Use (EULA): https://keendigital.co/#/terms
Privacy Policy: https://keendigital.co/#/privacy

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Cardia Fast Pro | $14.99 | per year |



## Version history (last 1 release)

### 1.0.0 — 2026-02-25

No release notes.

## More apps by Tuong Nguyen

- [Cardia Sleep](https://appshunter.io/ios/app/cardia-sleep/id6759352829)

All apps by Tuong Nguyen: https://appshunter.io/developer/1878188325

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-21.*