Fastrack

A fasting tracker for the Apple Watch. I fast most days and wanted something that lived on my wrist: start a fast, glance at the ring, see what my body is doing, and log it without reaching for my phone. Most fasting apps are bloated and want a subscription. This one does one thing.

The logo doubles as the interface: the mark fills bottom-up as the fast runs, so it reads the second you raise your wrist. Pick a preset, watch it fill, and learn what your body is doing in each phase as the hours pass.

The mark is the interface: it fills bottom-up as the fast runs.

Every fasting app I tried wanted an account, a subscription, and my phone in the loop. A fast is a start time and a goal; the tracker should live where the glance happens. So Fastrack is watch-only by design. No iPhone app, no accounts, no analytics, nothing leaves the device.

The other bet was making the brand do the work. The mark, stacked bars clipped to a circle, is the app icon, the complication glyph, and the progress gauge itself. One shape carries the whole app.

• Quick-start presets: 12:12, 13:11, 16:8, 18:6, 20:4, 24h, or a custom length. One tap starts the fast
• Logo gauge: The mark itself is the progress display, filling bottom-up in silver as the fast runs
• Phase education: A live read on the metabolic phase you're in, from digesting to deep ketosis, with the next milestone counting down
• History and streaks: A calendar of past fasts you can edit day by day, current and longest streak, and weekly trend charts
• Schedule and reminders: Optional phase and goal alerts plus a daily start reminder, local notifications only
• Weight log: Optional body-weight tracking through Apple Health, with edit and delete for logged entries
• Complications: A corner complication and a Smart Stack card with live fast status

The physiological milestones the app surfaces while a fast is running.

• 0 to 4h, Digesting: Blood sugar rises, insulin active
• 4 to 8h, Post-absorptive: Blood sugar stabilizing
• 8 to 12h, Early Fasting: Blood sugar drops, fat burning begins
• 12 to 14h, Metabolic Switch: Ketone production starting
• 14 to 18h, Fat Burning: Ketosis ramping up
• 18 to 24h, Autophagy: Cellular cleanup accelerating
• 24h and up, Deep Ketosis: Growth hormone elevated

Monochrome at its core, derived entirely from the logo: black, white, and greys on a pure black canvas with a subtle film grain. Four selectable accent themes (Graphite by default, plus Ember, Fern, and Tide) layer a single hue over that base; surfaces and tracks stay grey. Liquid Glass surfaces for the controls, SF Rounded throughout. Secondary actions live below the fold, so the gauge always owns the screen.

SwiftUI on watchOS 26, standalone, so it runs without the phone. Swift Charts for the trends, HealthKit for an optional weight log, local notifications for the reminders.

In active build, July 2026. The landing site is live with the privacy policy, and the App Store listing is next. Private repo for now.