BeastInterval | HIIT Timer With 18 Programs, Custom Builder, Charts and Achievements - SwiftUI

BeastInterval – HIIT Interval Timer for iOS

BeastInterval is a complete, App Store ready HIIT and interval training timer built with SwiftUI and SwiftData. It ships with 18 professionally designed workout programs, a custom workout builder, full workout history with charts, a 47 badge achievement system, sounds, haptics, dark mode and a complete StoreKit 2 subscription paywall with a free trial flow.

Demo Instructions

• This app is 100 percent offline. There is no login and no demo credentials are needed.
• Download, open in Xcode, run on a simulator or device and start training immediately.
• Free tier: 3 completed workouts. The Premium paywall (custom workouts, history, achievements) uses StoreKit 2 sandbox subscriptions – see the Configuration section in the documentation to connect your own products.

Everything the App Does

• 18 built-in workout programs: Classic HIIT, Tabata, EMOM, AMRAP, Pyramid, 40/20, 15/45, Strength, LISS, 20/40, Sprints, 1-Minute, Boxing, Circuit Training, Tabata Sprint, Plyo Training, Endurance, Speed and Agility
• Animated circular progress timer that changes color between work and rest phases
• 3-2-1 pre-workout countdown with sound and haptic feedback
• Bundled audio cues: countdown, go, rest, final round and completion sounds
• Haptic feedback on every phase change (countdown, go, rest, success)
• Custom workout builder: pick active time, rest time and rounds (up to 30)
• Pyramid program with progressive work intervals (10 to 50 seconds)
• Program detail overlay with rounds stepper (fixed rounds for Tabata style programs)
• Workout history list with completed / interrupted status and delete confirmation
• Stats dashboard: current streak, longest streak, total workout time, completion rate, average round duration, most active day
• Swift Charts 7 day activity chart
• 47 achievements with progress bars: general, streak and per workout type badges
• StoreKit 2 auto-renewable subscription paywall: yearly and monthly plans, 3 day free trial toggle, SAVE percent badge, restore purchases, terms and privacy links
• Free tier meter (3 free workouts) that upsells the paywall automatically
• 3 page onboarding flow
• Settings: appearance picker (System / Light / Dark), voice feedback toggle, manage subscriptions, restore, rate the app, contact support, terms and privacy
• Full dark mode support with custom color assets
• Rate prompt after every 10 workout sessions (SKStoreReviewController)
• SwiftData persistence with CloudKit sync support and automatic local fallback

Technology

• Language: Swift 5, SwiftUI
• Data: SwiftData (iOS 17+), CloudKit ready with local fallback
• Purchases: StoreKit 2 auto-renewable subscriptions
• Charts: Swift Charts
• Audio / Haptics: AVFoundation, UIKit haptics
• Minimum: iOS 17.0, iPhone only, portrait
• Requirements: Xcode 15+ (Xcode 16 recommended), no third-party dependencies, no CocoaPods / SPM packages

What the Buyer Gets

• Complete Xcode project source code (SwiftUI)
• All assets: app icon, color system, sound files
• Step by step documentation.html with embedded screenshots
• Instructions to rename the app, change the bundle ID, replace the icon and re-skin the whole theme from one place (asset catalog colors)
• Configuration guide for StoreKit products, App Store ID, support email and legal URLs
• App Store submission checklist

Development Disclosure

Portions of this template’s source code were developed with AI-assisted tools. All code has been reviewed, tested and is fully functional.

Note: This is a source code template. Xcode knowledge is required to build, customize and submit the app to the App Store.