Sundial is a free, comprehensive app that is the best tool for tracking the sun and moon and creating timely, detailed alerts. It is designed for iPhone, iPod, and iPad.

Sundial supports the display of both solar and lunar data on a 24-hour wheel. This makes it possible to view the position of the sun and moon throughout the day.

It also includes a widget to display the current position of the sun and moon at any time on your home screen. It's very easy to use and even includes a built-in timer function.

The built-in time wheel allows you to choose the start and end time of your alerts.

The app includes a calendar that displays the most relevant times for each alert.

The built-in widget allows you to display any alert at a glance.