It is the succeeding app that renewed "Simple Moon Phase Widget".

Improved point:
- Upgraded calendar (Variations of the background, Additional data, MoonSign and Mercury retrograde, etc.)
- Lightweighting of app capacity
- Notification is possible without setting the widget to the home screen
- Change of the moon color of the widget is possible in trial

Function:
- When you tap the date on the calendar to migrate to the detail screen that to display the large moon image.
- Detailed data is age of the moon, the distance to the moon, percent illuminated, time of the moonset/moonrise, Moon sign, Mercury retrograde.
- Notify full moon and new moon, first quarter, last quarter in the status bar.
- Full moon and new moon, first quarter, last quarter will be announced in the widget.
- Widget is resizable.
- There is also a memo function on the calendar.

★ There is a paid function to change the color of the moon.

Notice:
* Need permission of Storage and Location. 
* This app does not change the wallpaper. Please prepare wallpaper by yourself.
* This app is not provided image to completely reproduce the libration of the moon.
The position of the pattern of the moon phase, such as craters, shifts from a fact a little periodically.

What is Libration:
'In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.'
In Wikipedia: The Free Encyclopedia. 
Retrieved from http://en.wikipedia.org/wiki/Libration

It is a simple moon phase calendar. There is also a widget.