Designed for Android Wear but also works on other devices.

Couldn't be easier! Instructions:

1. Start app

2. Tap screen when you see a lightning

3. Tap again when you hear the thunder

For a more immersive experience, after tapping the screen once, the calculation is shown in real time. After tapping the screen the second time a highly accurate distance is displayed.

Designed to be as simple and lightweight as possible.