An interval timer, and the field tests that go with it

Free, no account, no subscription. Supported by ads.

What it does

True random beeps

Most timers fire on a fixed interval, which lets the body anticipate. Burst can scatter the cues at random inside a round: you pick the duration and how many beeps, and the engine spreads them unpredictably. The rhythm stays unpredictable from one round to the next.

It is built for boxing and combat sports (the punch lands on the cue, whenever it comes), agility work (change direction the second the beep lands), and any reaction training where anticipation defeats the point of the drill.

Group mode

On shuttle-style tests, one phone is enough for a group of up to 40. Names go in before the session; during the test you tap each participant the moment they stop, and their level is locked in. Past twelve names, a search field filters the list during the run. At the end you get the full ranking with each person's level, speed and estimated VO₂max, copyable in one tap.

It is meant for a physical education class, a preseason team assessment, or a squad test.

Workouts

• Intervals — work and rest, rounds, optional exercise labels.
• Pyramids — automatically increasing or decreasing intervals.
• Distance reps — 10 × 100 m, manual lap stop with split times.
• Ready-made presets — Tabata, HIIT, EMOM, AMRAP, circuits, mobility.
• History — sessions and test results are kept, with progress per tested capacity.

Field tests included

Each test uses its original protocol — starting speed, increment, stage length, cue spacing — and the result is computed with the reference formula for that test.

• Beep test / 20 m shuttle run (Léger & Lambert) — maximal aerobic speed and VO₂max.
• 30-15 Intermittent Fitness Test (Buchheit) — intermittent end-of-test speed.
• Gacon 45/15 — maximal aerobic speed.
• Yo-Yo Intermittent Recovery, levels 1 and 2 (Bangsbo) — distance covered and VO₂max.
• Cooper 12-minute and 6-minute — distance, aerobic speed, VO₂max.
• 2 km, T-Test, repeated sprints, breath control, cycling power.

Full protocols and level tables are published in French on the tests page and the beep test page.

Common questions

Is Burst free?

Yes. Every feature works with no account, no subscription and no in-app purchase. The app is supported by advertising: one ad appears after a finished session. The effort itself is never interrupted.

Does it need a connection?

No. Timing, tests and history all work offline.

Which languages?

English, French, Spanish, Portuguese, German, Italian, Chinese, Japanese, Hindi and Indonesian. The app follows the phone language; the choice can be changed in Settings.

Who makes it?

Molven Apps, an independent developer. Available on the App Store and on Google Play.