A free program for Android, by RED HAT.

If you want to use a stopwatch with precise timing, try the Audio Stopwatch – Accurate Ti application. This stopwatch functions similarly to a standard stopwatch, but with a few advanced modifications.

To start the timer, press the start button. The timer will begin counting immediately and will trigger audio on its own; all you have to do is turn up the volume on your phone. You can check your readings by stopping the stopwatch at any time. You can reset it whenever you want.

This application has a user-friendly interface for easy navigation, so there are no complicated buttons to worry about.

Install and see this app for yourself. Available on Google Play