SimpleMoon is a useful and very simple tool for finding out the phase and illumination of the moon. It's a great app for people interested in astronomy or moon studies.

It will give you all the information you need, you can see the phase and illumination for any day in the near future. If you want to know about the past, you can choose to see the last 1000 days or you can choose to see the past five years. The app will keep you up to date with the phase and illumination for any day in the future. You can choose to see the phase and illumination for your location, as long as your location is within the current year and is within 10 days of the current day.

When you first open the app, you will be asked whether you want to view the moon's phase and illumination for today or for the past.