Surge Interval Blast

Surge Interval Blast is a straightforward HIIT timer built for people who want control over their interval training without any extra friction. No accounts, no subscriptions, no internet required — everything runs locally on your device.

Set the number of rounds, define your work and rest durations, and start your session. The app tracks each phase clearly on screen and sends vibration alerts when it's time to switch, so you never have to glance at your phone mid-rep.

Key features:

- Customizable work and rest intervals — set exact durations for each phase
- Round counter — define how many rounds your session includes
- Visual phase indicator — clearly shows whether you are in a work or rest phase
- Haptic alerts — vibration feedback signals phase transitions
- Clean timer display — large, readable countdown at the center of the screen
- Compact, card, or grid view modes in settings
- Font size options: Small, Medium, or Large
- Onboarding walkthrough on first launch — can be replayed from settings
- Fully offline — no data ever leaves your device

The interface is designed to be readable at a glance during a workout. Dark background, high-contrast phase colors, and a minimal layout keep distractions out of the way. Whether you are doing a quick 4-round Tabata or a longer circuit session, Surge Interval Blast stays out of your way and keeps you on track.