Crontab UI - Easy and safe way to manage your crontab file
Scheduled tasks - GNOME GUI for configuring a users' cron (automatic jobs). Some of its features are:
024h Lucky Reminder - 024h Lucky Reminder is a reminder software for home and office.
Date Reminder - Date Reminder reminds you of recurring or nonrecurring events, like birthdays, bills to pay...
Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
Holiline Reminder - Holiline Reminder is both an event reminder and a calendar.