Docker Hub - Docker Hub is a cloud-based registry service
SendRecurring - SendRecurring allows you to setup, send, and maintain scheduled email reminders.
Apache Mesos - Apache Mesos abstracts resources away from machines, enabling fault-tolerant and elastic distributed systems to easily be built and run effectively.
Recurrr - Send recurring emails
Keep In touch - Keep in touch with thousands of people
FollowUpThen - The simplest way to schedule an email reminder