Intervelio | HIIT Interval Timer With Voice Announcements, Haptics and Health Sync – SwiftUI

Intervelio – Precision Interval Timer (SwiftUI + SwiftData)

Intervelio is a premium, 100% offline interval timer for HIIT, Tabata, boxing, running and Pomodoro sessions. It ships as a complete, production-ready Xcode project with a sleek dark UI, phase-colored countdown ring, voice announcements, haptics, Apple Health sync and automatic workout history – ready to reskin and publish as your own App Store product.

Demo Instructions

• The app is 100% offline – no login and no demo credentials are required.
• Open the project in Xcode 15 or newer and press Run on any iOS 17+ simulator or device.
• Five preset timers (Tabata, HIIT, Boxing, Pomodoro, Stretch) are seeded automatically on first launch.
• All data is stored locally with SwiftData. There are no servers, accounts or API keys.

Everything the App Does

• [x] 3-page animated onboarding flow with skip option
• [x] Custom splash screen with pulsing logo animation
• [x] Home dashboard with workout stats (workouts done, total minutes trained)
• [x] Live search across all saved timers
• [x] Filter tabs: All / Presets / Favorites
• [x] Five built-in presets: Classic Tabata, HIIT Cardio Blast, Boxing / Martial Arts, Pomodoro Study Session, Daily Stretch and Mobility
• [x] Create and edit fully custom timers: prep, warm-up, work, rest, rounds, cool-down
• [x] Live proportional workout timeline preview with color-coded phases
• [x] 8 accent colors and 10 SF Symbols icons per timer
• [x] Favorite, duplicate, edit and delete timers (context menu + buttons)
• [x] Full-screen running session with animated circular countdown ring
• [x] Distinct color per phase: prep, warm-up, work, rest, cool-down, completed
• [x] Pause / resume, skip next segment and restart previous segment controls
• [x] Overall workout progress bar and total remaining time
• [x] End-workout confirmation alert
• [x] Animated workout completion screen with trophy, total time and rounds
• [x] Automatic workout history (SwiftData) with summary cards and per-log details
• [x] Delete single history logs or clear all history
• [x] Apple Health / HealthKit integration – saves completed workouts with estimated active energy
• [x] Local notifications keep phases on track when the app is in the background
• [x] Sound cues: countdown beeps, transition tones and completion chime
• [x] Voice announcements of every phase using on-device speech synthesis
• [x] Haptic feedback (light, heavy and success patterns) on transitions and actions
• [x] Settings: toggle sounds, haptics and voice announcements
• [x] Settings: authorize HealthKit, restore default presets, replay onboarding
• [x] Rate app (StoreKit review prompt), share sheet, privacy policy and terms sheets
• [x] Empty states for timers list, search results, favorites and history
• [x] Forced dark theme with a modern neon-on-black design
• [x] Full accessibility labels on interactive controls

Technology

• Language: Swift 5, SwiftUI only (no storyboards)
• Persistence: SwiftData (offline, no backend)
• Minimum deployment target: iOS 17.0
• Frameworks: SwiftUI, SwiftData, AVFoundation, AudioToolbox, UserNotifications, HealthKit, StoreKit
• Third-party dependencies: none – pure native
• Architecture: MV-style separation – Models / Views / Services / Theme