FastTempo vs ChronoFast AI
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
FastTempo
This app provides a straightforward timer to help users maintain consistent eating and fasting windows. It focuses solely on timing, offering a clean visual display and seamless integration with smartwatches. Features include flexible streak tolerance and gradual fasting adjustments for beginners.
- 24-Hour Visual Timer
- Apple Watch Integration
- Flexible Streak Tolerance
- Gradual Fasting Adjustments
- Smart Reminders
- Automatic Schedule Following
- Fasting Pause Functionality
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FastTempo is an intermittent fasting timer for iPhone and Apple Watch. Set your eating window, follow your schedule, and track your fasting streaks. Why FastTempo? We built the fasting app we wanted to use. Focused, honest, and designed for your wrist. While other apps pile on meal logging, workout libraries, and aggressive upsells, FastTempo respects your time and your wallet. FEATURES - 24-Hour Visual Timer - See your eating and fasting windows at a glance with a clean circular display - Apple Watch First - Start and end eating windows directly from your wrist (requires Premium). Complications show your status without opening the app. Works even when you leave your phone at home. - Flexible Streaks - Life happens. Our adjustable minute tolerance rewards consistency without punishing minor variations. Up to 120 minutes tolerance. - Slide Into Fasting - New to fasting? We'll gradually shift your eating window over 7-10 days instead of throwing you into 16:8 on day one - Smart Reminders - Gentle notifications when your window opens and before it closes with customisation. - Follow Schedule Automatically - FastTempo will stop and start your eating window automatically but still give you notifications when to fast and eat. - Pause Fasting - Take a break through a date you choose. Your timer pauses immediately, your history stays intact, and your regular schedule resumes automatically at local midnight after the selected date. WHAT WE DON'T DO FastTempo is intentionally focused. We don't track calories, scan food, suggest recipes, or ask what you ate. Time-restricted eating works by when you eat. We handle the timing, you handle the rest. SUBSCRIPTIONS Premium offers annual billing. Eligible subscribers may receive a two-week free trial on the annual option where that offer is available. Annual billing starts after the trial. Trial eligibility depends on your App Store subscription history and the offer shown at purchase. Where available, Premium also offers monthly billing with a 12-month commitment. This option requires the full 12-month commitment. Check the purchase screen for the available options, local price, payment schedule, trial eligibility, and renewal terms before subscribing. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
ChronoFast AI
This app acts as an AI coach for intermittent fasting, helping users understand if their food intake breaks their fast. It provides detailed metabolic insights, tracks progress, and offers social features for fasting with friends.
- AI-powered 'Did I Break My Fast?' analysis
- Live Activity and Dynamic Island integration
- Detailed metabolic stage tracking
- Apple Health integration for activity and sleep
- AI meal scan and barcode scanning
- Social fasting features and leaderboards
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Most fasting apps are a countdown. ChronoFast AI is a coach that answers the question you actually have at hour 11: does this break my fast? DID I BREAK MY FAST? Type what you had, or snap a photo of it. The AI weighs it against the exact stage your fast is in and gives a straight verdict — Intact, Impacted or Broken — with what it does to insulin, fat burning and autophagy. If it is genuinely broken, one tap ends or restarts the timer. ON YOUR LOCK SCREEN ALL DAY Start a fast and the Live Activity stays with you for the whole thing, drawing the same dial the app does: a ring sweeping through every stage colour, each one checked off as you pass it, with your stage, time elapsed, when the next stage lands and the clock time you finish. Add 250 ml logs your water; End fast opens the app's own confirmation, with undo. The Dynamic Island gives the dial and percentage at a glance, the full status on a press and hold — and one switch in Settings turns it all off. A TIMER THAT SHOWS ITS WORKING • A live dial with your percentage of goal at the centre • A 24-hour band that shows when you eat, and whether your window is drifting later • A named stage track — Fed, Fat Burning, Ketosis, Deep Autophagy — hour-stamped for your plan • Home Screen widgets in two sizes, plus a Lock Screen circular accessory • 12:12 through 20:4, 23:1 OMAD, extended 24h to 72h fasts, or your own custom window • Streak repair: one free rescue a month for a single missed day SCIENCE YOU CAN CHECK Every metabolic stage carries its source — the NEJM fasting review, the Nobel-winning autophagy research — named, dated, and honest where the evidence is still early. The Metabolic Wave glucose curve is clearly labelled as an educational simulation modelled from your clock, never measured from your body. No bro-science, no numbers we cannot know. YOUR ACTIVITY AND SLEEP COUNT With Apple Health connected, ChronoFast reads sleep, resting heart rate, HRV, steps, workouts and active energy, each compared against your own 7-day average. A fasted walk shows as real metabolic progress. A rough night, and the app eases off instead of pushing you to extend. It writes back too — water, weight, nutrition and completed fasts — with a switch for each. FOOD, WATER AND WEIGHT IN ONE PLACE • AI meal scan from a photo, plus barcode scanning for packaged food • Calories and macros on one compact card, with rings that fill as you log • Hydration goal set from your body weight, with reminders that never collide with a stage alert • Weight trend with a projected goal date that shows its confidence band YOU ARE NOT ALONE AT HOUR 16 Fast with buddies added by QR or friend code, see who is fasting right now, send high-fives, join weekly and monthly challenges, log how the fast actually feels on a 1-5 mood scale, and climb a global leaderboard. A shareable weekly recap rolls up your last 7 days. PROGRESS THAT MAKES SENSE A 28-day consistency grid read three ways — fasting, weight and water — a day-by-day log for every metric, and plain-language observations about your last four weeks, each with its evidence. BUILT TO BE TRUSTED 18 languages including full right-to-left Arabic. An adults-only age gate before any health question. A legal centre in plain English, explicit AI-processing consent, and crash reports that never carry your name. Moving phones? Export everything at once. FREE AND PRO The timer, stages, logging, community and daily AI coaching are free. Pro unlocks unlimited AI insights and food scans, all five coach personas, predictive goal dating, the glucose chart and a 100% ad-free app. IMPORTANT ChronoFast AI is for education and general wellness, not a medical device: it does not diagnose, treat or prevent any condition, and AI output can be wrong. Talk to a doctor before fasting if you are pregnant or breastfeeding, under 18, diabetic, on medication, or have a history of disordered eating. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is rating: ChronoFast AI at 5.0 against FastTempo's 1.0. ChronoFast AI also leads on update cadence (every 2 weeks vs every 2 months) and iOS requirement (17.0 vs 26.0). FastTempo's advantage is ads (none vs shown). On price, ratings volume, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. FastTempo sells 1 in-app purchase, starting at $19.99 per year and ChronoFast AI sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.
ChronoFast AI holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
FastTempo ships an update every 2 months, ChronoFast AI every 2 weeks. The most recent releases landed on October 24, 2026 and October 31, 2026 respectively.
| Parameter | FastTempo | ChronoFast AI |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Requires iOS | 26.0 | 17.0 — better |
| Further details — not scored | ||
| Size | 14 MB | 121 MB |
| Age rating | 4+ | 17+ |
| Developer | Andrew Ford | Soundarya Srinivas |
Customer experience
FastTempo
ChronoFast AI
In-app purchases
FastTempo
- FastTempo Premium14 Days trial$19.991 Year
ChronoFast AI
- ChronoFast-AI-Monthly-Yearly$4.991 Month
- ChronoFast-AI-Monthly-Yearly7 Days trial$39.991 Year









