Recurrr - Send recurring emails
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
SendRecurring - SendRecurring allows you to setup, send, and maintain scheduled email reminders.
DocuWork - All-In-One Back-Office Manager for Organizations.