Intervelio

Intervelio is a complete native iOS interval training timer built in SwiftUI. Build fully custom workouts with work, rest, rounds, warm-up, cool-down and prep segments, run them on an animated session screen with voice, sound and haptic cues, and track everything in an automatic history log. Completed workouts sync to Apple Health, and upcoming phases keep guiding you from the lock screen via local notifications.

Highlights

• Custom timer editor: work, rest, rounds, warm-up, cool-down and prep segments, 8 accent colors and 10 icons per timer
• Five built-in preset timers seeded on first launch (editable in one array)
• Animated session screen with pause, resume, skip and segment restart
• Voice (text-to-speech), sound and haptic cues, each toggleable independently in Settings
• Local notifications for upcoming phases so the timer guides you from the lock screen (no push server)
• Apple Health sync: completed workouts saved as HKWorkout (HIIT type) with estimated energy burn
• Automatic history logging with duration and rounds, per-log delete and clear-all
• Home dashboard with workouts done, total time trained, search and preset/favorite filters
• Splash and onboarding flow, privacy manifest included
• One-hex re-skin: find-and-replace FF5E3A and the whole app follows your brand color

Technology

• SwiftUI with SwiftData persistence (IntervalTimerModel, WorkoutHistoryModel)
• WorkoutEngine: a dedicated interval state machine isolated from the views
• NotificationManager, SoundHapticManager (TTS) and HealthKitManager services
• DesignSystem.swift: all phase colors, palette, icons and hex utilities in one file
• iOS 17+ deployment target, zero third-party dependencies

Requirements

• macOS with Xcode 15 or later
• Apple Developer account for device testing; App Store Connect will ask to justify the HealthKit capability (workout tracking)
• No accounts, keys or external services: the app runs fully offline

What You Get

• Full readable SwiftUI source: onboarding, home, editor, session, history and settings
• Ready-to-build Xcode project with app icon, HealthKit entitlement and privacy manifest
• documentation.html with embedded screenshots: setup, re-skin walkthrough, notifications and HealthKit notes, App Store publishing checklist
• README.md and 9 app screenshots including a teal re-skin example

Please note: this is a source code template, not a fitness or medical product. Building and customizing it requires basic knowledge of Swift and Xcode. If you have questions, use the contact form on the site, I usually reply within 24 hours.