Custom start sequence
Set the intervals between “On Your Marks,” “Set,” and the pistol sound to match your practice goal.
Sprint start practice for athletes and coaches
Starter Kit
Play “On Your Marks,” “Set,” and a pistol sound from your iPhone. Set exact cue intervals or randomize them for less predictable, race-like practice—whether you train alone, with a team, or as a coach.
21,000+ downloadsas of September 20, 2026
Download on the App Store
CORE FEATURES
Race-like sprint start practice with one phone
Random start timing
Randomize cue intervals so the pistol timing is harder to predict and the reaction practice feels more realistic.
Reaction-time measurement
Measure the reaction at the start and use the result to review progress across training sessions.
Video review
Record the start movement, then check body position, form, and the response to the sound.
APP SCREENS
Configure the session you need
QUICK ANSWERS
Frequently asked questions
What is Starter Kit?
Starter Kit is an iPhone app for sprint start practice and reaction-time training. Individual athletes, teams, and coaches can use it.
Can I customize the start cue timing?
Yes. Set the intervals between “On Your Marks,” “Set,” and the pistol sound, or randomize those intervals for less predictable practice.
Can it measure reaction time?
Yes. The app can measure the reaction at the start so you can use the result when reviewing a training session.
Can I review my start on video?
Yes. Record the start movement and review your form and reaction afterward.
DEVELOPER
Created by Koki Osada
Independent iOS developer, medical doctor, and runner. Starter Kit was created so sprinters can practice starts without large or specialized equipment.