SendRecurring - SendRecurring allows you to setup, send, and maintain scheduled email reminders.

Thankster - Automagically send hand written cards

Recurrr - Send recurring emails

Thankbot - Drive more business with handwritten notes

Followup.cc - FollowUp for email is a lightweight productivity suite that keeps your conversations and tasks from slipping through the cracks. Set perfectly timed reminders that arrive at the top of your inbox, right when you need them.

Socialkeeper - Cultivate your friendships