Simple Moon Phase Calendar is a free iPhone app developed by Fumihiro Takahashi. As a lifestyle application in the weather subcategory, it serves as a convenient tool for tracking lunar phases and related information. With its user-friendly interface, it allows users to tap on the date cell to access a detail screen, where they can find a wealth of lunar data.

The app provides detailed information such as the moon phase, moon age, distance, percent illuminated, moon sign, constellation, Mercury retrograde, moonrise, moonset, and more. Alongside these features, there is also a note function and a handy widget for quick access to lunar information.

Additionally, Simple Moon Phase Calendar offers the option to receive notifications for significant lunar events, including full moon, new moon, first quarter, last quarter, and the beginning and end of Mercury retrograde.

Whether you're an avid stargazer, a nature enthusiast, or simply curious about lunar cycles, Simple Moon Phase Calendar provides a convenient and comprehensive way to track and explore the moon's various phases and related information.