FollowUpThen - The simplest way to schedule an email reminder
Crypto Price Tracker - An app for all your cryptocurrency needs!
Right Inbox - Schedule Emails in Gmail To Be Sent Later
Bumper - Bumper is a stripped down version of FollowUpThen, followup.
LetterMeLater.com - LetterMeLater.com allows you to send emails to anyone, with the ability to have them sent at any future date and time you choose.
Twitter Ads - Twitter offers targeted ad placement on their ad platform.