FollowUpThen - The simplest way to schedule an email reminder
Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Simply Remind Me - Free email and text reminder service so you don't forget the important things in life!
SnapTimer - SnapTimer is a simple, free, portable countdown timer for Windows.
Auto Mail Sender - Auto Mail Sender Standard Edition official page. A powerful and easy-to-use eMail scheduler.
wnr - Better than pomodoro, this timer app balances work and rest.