ONE vs Vasten
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ONE
This app simplifies intermittent fasting with a one-tap timer and progress tracker. It guides users through fasting stages, offers various plans, and provides insights into body changes. The focus is on building consistent habits without unnecessary complexity.
- One-tap fasting timer
- Live fasting stage tracking
- Multiple fasting plan options
- Daily streak tracking
- Weight and water tracking
- AI-powered progress summaries
- Offline functionality
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Fasting made simple. Start a fast in one tap, watch your body move through each stage, and build the streak that actually changes things. ONE is an intermittent fasting tracker for people who want the habit, not the homework. No account. No clutter. Just the timer, the stages, and your progress. CHOOSE YOUR PLAN • 12:12, 14:10, 16:8, 18:6, 20:4 and OMAD (23:1) • Flexi mode for open-ended fasts • A difficulty rating on every plan, so you pick one you'll actually keep • Custom Timer for any length you like — free, no upgrade • Change plan any time. Nothing is locked in. WATCH WHAT'S HAPPENING • Live fasting stages: blood sugar falling, fat burning, ketosis, autophagy • Know exactly when the next stage arrives • Plain-language explanation of what your body is doing, and why STAY ON TRACK • Reminders when your fast starts and ends • A notification as you reach each new stage • Fix your start or end time when life happens • Daily streaks that reward consistency, not perfection • Apple Health: your fasts written out, your weight read in — free SEE YOUR PROGRESS • Every fast logged automatically, nothing to fill in • Your recent fasts, free forever WHAT ONE PREMIUM ADDS • Your full fasting history, not just the last few • AI Coach — weekly and monthly written analysis of how you actually fast, what changed, and what to try next • Trends: streak calendar, fasting-hours charts and weight trend • Protein tracker, with a daily target set from your weight • Water tracking against a goal, right on the timer • Your own Quick Start lengths, tuned to the fasts you really do • Apple Watch app with complications — start and end a fast from your wrist • Home Screen widget and a Live Activity on your Lock Screen The timer, every plan, the stages and the Custom Timer are free. Forever. BUILT TO STAY OUT OF THE WAY • Start fasting in under a minute — no sign-up, no email • Optional account, so your history follows you to a new phone SUBSCRIPTION ONE Premium is an auto-renewing subscription, available monthly or annually. Payment is charged to your Apple Account at confirmation of purchase. It renews automatically unless cancelled at least 24 hours before the end of the current period, and your account is charged for renewal within 24 hours of the end of that period. Manage or cancel any time in your Apple Account settings. Medical disclaimer: ONE is for general wellness only and does not provide medical advice. Talk to a qualified healthcare professional before starting any fasting programme, particularly if you are pregnant, breastfeeding, diabetic, under 18, or have a history of disordered eating. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.fastingtime.co/privacy
Vasten
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Vasten does one job well: it keeps an accurate record of your fast. Start in one tap, see elapsed time and your goal on the main screen, and keep the timer visible through a Home Screen widget, Lock Screen Live Activity, and Dynamic Island. Reaching the goal never ends the fast automatically—you decide when it ends. Your history remains useful and under your control. Correct start and end times, review simple totals, import Vasten JSON or Zero history, export everything as JSON or CSV, or delete any record. Features: • One-tap start with an adjustable start time • Custom fasting goals from 1 to 168 hours • Clear widget goal progress and goal end times • Lock Screen and Dynamic Island Live Activity • Small and medium Home Screen widgets • Separate timer and 12-week fasting-activity widgets • Custom accent colors shared across the app and widgets • Editable history and summary statistics • Configurable local goal-time notification • Vasten JSON and Zero fasting-history import • Private device storage with private iCloud synchronization • JSON and CSV export • English and Dutch • No account, ads, analytics, or subscription Stage labels are general educational time ranges. They are not measurements of your body or medical advice.
Screenshots
Verdict
The clearest difference is in-app purchases: Vasten at none against ONE's 6. Vasten also leads on update cadence (every 2 days vs every 4 weeks). ONE's advantage is device support (4 vs 1) and iOS requirement (15.1 vs 26.5). On price and ads 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. ONE sells 6 in-app purchases, starting at $2.99 per 7 days. Vasten asks for nothing beyond the download.
ONE ships an update every 4 weeks, Vasten every 2 days. Both last shipped on October 31, 2026.
| Parameter | ONE | Vasten |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 4 weeks | Every 2 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Freemium | — |
| Devices | iPhone, iPad, iPod, Apple Watch — better | iPhone |
| Requires iOS | 15.1 — better | 26.5 |
| Further details — not scored | ||
| Size | 49 MB | 2 MB |
| Age rating | 17+ | 4+ |
| Developer | Create Rush | Dennis Van Dalen |
In-app purchases
ONE
- Standard Weekly$2.997 Days
- Premium Weekly$4.997 Days
- Standard Monthly$4.991 Month
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- Premium Monthly$9.991 Month
- Standard Yearly$49.991 Year
- Premium Yearly$99.991 Year
Vasten
No in-app purchases









