Onesheet CRM - The Simple CRM for Google Sheets
Bond - A simple app that reminds you to keep in touch with people
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.
Thankster - Automagically send hand written cards
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.
Thankbot - Drive more business with handwritten notes