Moon Phase Calendar by probadoSoft represents a specialized astronomical utility application delivering comprehensive lunar and solar tracking capabilities for Android devices. The application occupies a niche position within the astronomy software market, distinguishing itself through location-specific celestial data and notification systems that cater to both casual observers and dedicated astronomy enthusiasts. The application's core functionality centers around precise lunar phase tracking with real-time illumination percentages, countdowns to upcoming phases (new moon, first quarter, full moon, last quarter), and detailed timing information. Additional astronomical data includes sunrise/sunset times, twilight duration calculations, and zodiac positioning, creating a multifaceted celestial observation tool. The notification system allows users to set alerts for specific lunar events, while location-based customization ensures accuracy for regional astronomical phenomena. User experience demonstrates generally intuitive navigation with a tab-based interface separating moon, sun, and calendar features. The home screen provides immediate access to current lunar phase with graphical representation, while dedicated sections offer deeper astronomical data. Real-world usage patterns indicate particular utility for gardening schedules, spiritual practices, photography planning, and astronomical observation, with widgets enabling quick glanceable information without opening the full application. User feedback trends reveal generally positive reception with specific praise for functionality depth, though technical issues and intrusive prompts have drawn criticism. Ashley B (August 16, 2025) noted satisfaction while requesting additional moon nomenclature features, while Tina Teichroeb (August 13, 2025) reported functionality degradation after updates. Multiple reviewers including Rose C (August 6, 2025) cited excessive rating prompts as a significant usability concern despite otherwise positive experiences. The application demonstrates notable strengths in data comprehensiveness and customization options, though reliability concerns following updates and aggressive monetization tactics present limitations. Ideal use cases include regular lunar cycle monitoring for spiritual practices, astronomical photography planning, and educational purposes where detailed celestial timing information provides practical value beyond basic phase tracking.