SendLater - Email scheduler for Mac Mail.
Large - On-demand Slack bot that can get you anything for the office
Right Inbox - Schedule Emails in Gmail To Be Sent Later
Awesome PA for Startups - On-demand personal assistant over Slack & SMS
SndLatr - SndLatr is a Gmail plugin that makes it easy to schedule emails to be sent automatically at a later time.
DocuWork - All-In-One Back-Office Manager for Organizations.