Digital Clock 4 - Beautiful customizable clock with plugins
Right Inbox - Schedule Emails in Gmail To Be Sent Later
System Scheduler - System Scheduler for Windows, Free Task Scheduler Software replace Microsoft Windows Task Scheduler
Recurrr - Send recurring emails
VisualCron - VisualCron is an automation, integration and task scheduling tool for Windows.
FollowUpThen - The simplest way to schedule an email reminder