Reminder apps are digital tools designed to help users keep track of tasks, appointments, and important dates. They send notifications or alerts to remind users of their scheduled activities, ensuring that nothing is forgotten. These apps can be used on various devices, including smartphones, tablets, and computers, making it easy to access reminders anytime. Many reminder apps offer features like recurring reminders, customizable notifications, and integration with calendars. Popular examples include Google Calendar, Todoist, and Microsoft To Do. These features help users stay organized and manage their time effectively, enhancing productivity in both personal and professional settings.