FastingWindow is a simple, no-account intermittent fasting tracker. Tap to start a fast, see a live progress ring as hours tick by, and watch your body move through its natural fasting stages — from digestion to fat burning to deep ketosis.
Features
Live fasting timer
A glowing progress ring fills as your fast progresses. The center shows elapsed time down to the second, with a countdown to your goal when you’re close. A color-coded glow shifts as you move through stages.
Body stage tracking
FastingWindow tracks where your body is in the fasting process and tells you what’s happening:
- Digestion (0–4h) — Working through your last meal
- Stabilizing (4–8h) — Blood sugar settling, energy stabilizing
- Fat Burning (8–12h) — Glycogen depleted, fat metabolism begins
- Ketosis (12–16h) — Ketone production underway
- Deep Ketosis (16h+) — Full ketosis, peak fat burning
Fasting schedules
Choose from presets or dial in exactly what works for you:
- 16:8 — 16 hours fasting, 8-hour eating window
- 12:12 — A gentler 50/50 split
- Custom — Any ratio from 1:23 to 23:1, set with a stepper
History and stats
Every completed fast is logged. The History tab shows your current streak, longest streak, total fasts completed, and total hours fasted. You can also export your full history as a CSV file.
Notifications
Optional reminders fire one hour before your eating window closes and one hour before your next fast is set to begin. You can also set a preferred daily start time to keep your schedule consistent.
Share your fasts
When you complete a fast, FastingWindow shows a summary card with your duration and stage reached. You can share it directly from the completion screen.
No account, no cloud
All data stays on your device. There’s no account to create, no server, and no internet connection required.
Pricing
FastingWindow includes a 60-day free trial. After that, unlock forever for a one-time $2.99 payment. No subscription, no recurring charges.
If you need to restore a previous purchase on a new device, use the “Restore Purchases” button in Settings.
Support
Questions, feedback, or something not working right? Email us at support@moonlabs.app and we’ll get back to you.
Common questions
Can I log a fast I already started?
Yes. When you tap “Start Fast,” you can pick any start time up to 24 hours in the past.
Can I log a fast that already ended?
Yes. When you tap “End Fast,” you can pick any end time between when you started and now.
I bought the app on another device — how do I unlock it?
Go to Settings and tap “Restore Purchases.” As long as you’re signed in with the same Apple ID, it will unlock for free.
My notifications aren’t showing up.
Make sure notifications are enabled both inside FastingWindow (Settings → Reminders) and in your iPhone’s Settings app under FastingWindow → Notifications.
How do I export my history?
Open the History tab and tap the share icon in the top-right corner. This generates a CSV file you can save to Files, email to yourself, or open in any spreadsheet app.