Atomic Fast vs Unthink
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Atomic Fast
This app combines intermittent fasting with AI-powered calorie and macro tracking. It analyzes your eating patterns, hydration, sleep, and activity to provide metabolic insights and a daily readiness score. Seamlessly integrates with Apple Health for a holistic view of your well-being.
- AI calorie and macro estimation from photos
- Intermittent fasting timer with metabolic phases
- Break-fast meal scoring and suggestions
- Connects meals and fasts for holistic insights
- Daily readiness score based on health signals
- Apple Health and Apple Watch integration
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Track your fasts through real metabolic phases, then snap a photo of your meal to log calories and macros in seconds — and see exactly how the two connect. Most fasting apps track time; most calorie apps track food. Atomic Fast connects both. Atomic Fast combines intermittent fasting, AI calorie tracking, macro counting, Apple Health insights, and hydration tracking in one app — made for people who already fast and want more than just a basic timer or food diary. FASTING TIMER WITH METABOLIC PHASES Track your fasts with a real-time fasting timer and estimated metabolic phase guidance. Follow your progress through clear visual stages, from digestion and transition to glycogen depletion, fat burning, ketosis, deeper fasting, and autophagy. Choose popular fasting schedules like 16:8, 18:6, 20:4, OMAD, or create your own custom plan. Adjust your goals anytime, and get fasting milestone notifications without the pressure. AI CALORIE TRACKING IN SECONDS Take a photo of your plate. Atomic Fast typically identifies foods in under 5 seconds and estimates calories, macros, and nutrients — like a smart AI calorie counter and macro tracker that actually understands what you ate. You can also log meals by: - Describing what you ate with text or voice - Scanning nutrition labels - Scanning barcodes - Searching the USDA food database - Adding meals manually when needed No more typing one ingredient at a time. BREAK-FAST SCORE The first meal after a fast matters. Atomic Fast scores your break-fast meal from 0 to 100, with practical suggestions on protein, fiber, carbs, and balance for a smoother transition back into eating. MEALS AND FASTS THAT WORK TOGETHER Most fasting apps track time. Most calorie trackers and food diaries track food. Atomic Fast connects both. See how your last meal affects your next fast, how your fasting consistency affects your eating patterns, and how nutrition timing may connect with sleep, recovery, and daily energy. METABOLIC INSIGHTS Atomic Fast helps you spot patterns across fasting, meals, hydration, sleep, heart rate, HRV, activity, and more. Interactive charts and daily insights help you understand habits like calorie trends, macro balance, fasting consistency, and how nutrition timing may connect with sleep, recovery, and energy levels. Daily insight examples: - "Ending eating by 7 PM dropped your sleeping heart rate by 4 bpm last week" - "On high-recovery days you hit your fasting goal 30% more often" Insights are calculated on your device. Your patterns stay yours. DAILY READINESS SCORE Wake up to a readiness score from key health signals: sleep, HRV, resting heart rate, activity, exercise, and respiratory rate. A simple guide to whether today is a good day to push your fast, stay normal, or focus on recovery. APPLE HEALTH AND APPLE WATCH Atomic Fast syncs 24 Apple Health data types: sleep, heart rate, HRV, steps, workouts, weight, respiratory rate, and more. Meals write 11 nutrients plus water back to Apple Health, keeping your nutrition data connected across your favorite health apps. HYDRATION TRACKING One-tap water logging. Smart reminders that fit naturally around your fasting routine. BUILT FOR EVERYDAY USE - Three themes including a signature Deep Purple mode - Two timer styles: Atomic Ring and Classic Ring - Smart notifications for fasting milestones, hydration, meal reminders, and weekly recaps - Awards and streaks to celebrate progress without pressure - Offline-first experience - Privacy-focused design - Apple Watch companion app ATOMIC+ The free version is the real product — fasting tracking, manual food logging, readiness score, daily insights, themes, and 7 AI meal scans per week, all free and ad-free. Atomic+ unlocks: - Unlimited AI meal scans - iCloud backup and data export Available as Atomic+ Monthly, Atomic+ Annual (with 7-day free trial), or Atomic+ Lifetime. Terms of Use: https://atomicfast.com/terms Privacy Policy: https://atomicfast.com/privacy
Unthink
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Your heart is racing. Your thoughts are looping. It's 1 am and you're replaying one sentence from three days ago. Unthink is made for exactly that moment. Open the app. Tap what you feel. Follow one guided minute. No course to finish. No streak to keep. No feed to scroll. Just one small thing to do right now, and then the next one if you need it. HOW IT WORKS • Six buttons, one for each kind of moment: heart racing, thoughts spiraling, can't sleep, overthinking about someone, restless, or just off. • Unthink picks a short exercise that fits. Most take about 60 seconds. • Afterwards it asks one question: better? If not, it offers a different one. • Around people? One switch, and you only get exercises nobody will notice. • At night the app turns dark and quiet on its own. WHAT'S INSIDE • Bloom, an AI assistant you can write to: tell it what is going round in your head, or paste the message you don't know how to answer. It helps you sort it and offers one exercise that fits. Bloom is an AI, not a therapist. • 26 guided exercises: breathing, grounding, body, thinking tools, sleep, and moments around other people. Each one explains in a sentence why it works. • Fact vs. Story: separate what actually happened from what your mind added. Stuck? Ask Bloom for other explanations. Keep the card. • Park the Message: write the text you want to send right now. Decide in 30 minutes. • Reality Check: park a worry, say what you fear, pick a date. Later, Unthink asks what really happened, and over time you see how often the fear was bigger than the outcome. • Wind Down: a quiet evening sequence of 5 or 12 minutes that ends without a finish line. • Your patterns: what works for you, when hard moments tend to show up, and how your worries compared with reality. • A widget for your Lock Screen and Home Screen: one tap to a calming minute. It never says what it's for. • One gentle check-in a day, at a time you choose. Or none at all. PRIVATE BY DESIGN • No account. No ads. No tracking. No analytics. • What you write and do stays on your phone. We never see it. • The one exception is Bloom, and only if you switch it on: what you write to Bloom is sent to Anthropic, whose AI writes the reply. It is not used to train AI, and Unthink keeps no copy. • One button deletes everything. PREMIUM Your first guided minute and the help screen are free. Unthink Premium unlocks all 26 exercises, Bloom, the three tools, Wind Down, your patterns and favorites. Try it free for 3 days. Bloom comes with a monthly allowance. • Monthly and yearly plans. The current price is shown in the app before you buy. • Payment is charged to your Apple ID at confirmation of purchase. • The subscription renews automatically unless it is cancelled at least 24 hours before the end of the current period. • Manage or cancel any time in your App Store account settings. ONE HONEST THING Unthink is a self-help tool. It is not a medical device, it doesn't diagnose or treat anything, and it doesn't replace therapy or medical care. If you are in crisis, please call your local emergency number or a crisis line. The app's help screen lists numbers for several countries and is always free. Terms of Use: https://getunthink.app/terms Privacy Policy: https://getunthink.app/privacy
Screenshots
Verdict
The clearest difference is update cadence: Atomic Fast at every 4 days against Unthink's every 3 weeks. Atomic Fast also leads on device support (3 vs 1). Unthink's advantage is iOS requirement (16.4 vs 18.0). On price, ads and in-app purchases 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. Atomic Fast sells 3 in-app purchases, starting at $4.99 per month and Unthink sells 2 in-app purchases, starting at $8.99 per month. Whichever you choose, the download price is not the number that matters.
Atomic Fast ships an update every 4 days, Unthink every 3 weeks. The most recent releases landed on October 28, 2026 and October 24, 2026 respectively.
| Parameter | Atomic Fast | Unthink |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (30 ratings) — better | — |
| Positive reviews | 96.3% of reviews | — |
| Number of ratings | 30 — better | — |
| Update frequency | Every 4 days — better | Every 3 weeks |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | — |
| Devices | iPhone, iPad, Apple Watch — better | iPhone |
| Requires iOS | 18.0 | 16.4 — better |
| Further details — not scored | ||
| Size | 22 MB | 53 MB |
| Age rating | 4+ | 17+ |
| Developer | Startise | Nico Lange |
In-app purchases
Atomic Fast
- Atomic+ Monthly$4.991 Month
- Atomic+ Annual7 Days trial$29.991 Year
- Atomic+ Lifetime$59.99
Unthink
- Monthly$8.991 Month
- Yearly3 Days trial$44.991 Year









