1CalendarS

1CalendarS helps you plan your day efficiently with flexible views (day, week, month, list) and quick editing. It supports cross-device calendar synchronization across Apple devices; changes update across iPhone, iPad, and Mac. You can customize event prompts for dates or times to stay on track.

The app is free to download and use, with an optional Premium membership unlocking advanced features. Subscriptions are offered as monthly ¥30.00 or yearly ¥168.00, charged to your iTunes account, and auto-renew unless canceled at least 24 hours before the current period ends. Privacy and terms are available at the provided URLs.