Calendar apps are digital tools that help users organize their schedules and manage time effectively. They allow individuals to create, edit, and share events, set reminders, and view their plans in various formats, such as daily, weekly, or monthly. Popular examples include Google Calendar, Apple Calendar, and Microsoft Outlook Calendar. These apps often sync across multiple devices, ensuring that users have access to their schedules anytime and anywhere. Many calendar apps also integrate with other applications, such as email and task management tools, making it easier to coordinate tasks and appointments seamlessly.