・Tiered premium features: First 2 groups free, payment required from 3rd group・Reminder notification system: Send notifications at a fixed time daily・Group management functionality: Add, delete, edit groups with duplicate checking・Exclusive notification control: Only selected groups notify, others auto-stop・Calendar integration: Group switching and title setting by date・Visual feedback: Icon status display (configured/unconfigured)・Error handling: Clear error messages and solutions・Multi-language support: Complete Japanese and English support・Foreground control: Notification suppression while app is in use・Database optimization: Stable data management using SQLite・Notification system: iOS-specific optimization with badge disabled・Lifecycle management: Appropriate processing based on app state・Initial setup assistance: User-friendly configuration prompts・Calendar dialog UI improvements: Radio button selection and responsive design・Localization enhancement: Multi-language support for "Clear Scheduled Settings" button・Date display standardization: Unified "2025/6/27" format in calendar dialogs・Calendar header optimization: Month-year display in "2025 / 6" format・Responsive calendar: Auto-adjustment for 6-week months and overflow resolution・Calendar spacing standardization: Uniform placement and improved visibility of all date cells・Input validation enhancement: Empty group title checking with alerts・Notification control bug fix: Prevention of unintended notification delivery during calendar selection・Exclusive notification scheduling: Reliable notification control for current day groups only・Debug logging enhancement: Transparency in notification operations and troubleshooting support・Data integrity assurance: Real-time synchronization of calendar and group data・Usability improvements: Intuitive operation flow and visual feedback

~Kouki Mori