Mobile
Workout Set Timer
Tech Stack
FlutterDartiOSBackground Processing
Overview
Workout Set Timer is a minimalist iOS timer app I built out of personal frustration — every workout timer I tried was either bloated with features I didn't need or unreliable when the phone was locked. This app does one thing well: it counts your sets with customizable work/rest intervals and keeps running in the background. You configure the number of sets, work duration, and rest duration, hit start, and it handles the rest with audio and haptic cues even when your screen is off. The UI is intentionally stripped down — large, readable numbers, high-contrast colors, and zero ads. Built with Flutter for iOS, it uses native background audio sessions to keep the timer alive.
Challenges
- •Keeping the timer accurate and running when the app is backgrounded or the screen is locked on iOS
- •Designing a UI simple enough to operate mid-workout with sweaty hands, while still being configurable
- •Managing audio session categories to play timer cues without interrupting the user's music
Solutions
- •Leveraged iOS background audio sessions with silent audio playback to prevent the OS from suspending the app, combined with precise timer logic using Dart isolates
- •Designed oversized tap targets, minimal navigation, and a single-screen flow where the most common action (start/pause) is always the largest button
- •Configured the audio session to mix with other audio sources, so timer beeps overlay on top of Spotify or Apple Music without pausing playback
Results
Published on App Store with positive user reviews